diff --git a/CHANGELOG.md b/CHANGELOG.md
index 524d48696a..8fabd3654f 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -1,3 +1,27 @@
+## 15.1.0 (May 20, 2016)
+
+### React
+- Ensure we're using the latest `object-assign`, which has protection against a non-spec-compliant native `Object.assign`. ([@zpao](https://github.com/zpao) in [#6681](https://github.com/facebook/react/pull/6681))
+- Add a new warning to communicate that `props` objects passed to `createElement` must be plain objects. ([@richardscarrott](https://github.com/richardscarrott) in [#6134](https://github.com/facebook/react/pull/6134))
+- Fix a batching bug resulting in some lifecycle methods incorrectly being called multiple times. ([@spicyj](https://github.com/spicyj) in [#6650](https://github.com/facebook/react/pull/6650))
+
+### React DOM
+- Fix regression in custom elements support. ([@jscissr](https://github.com/jscissr) in [#6570](https://github.com/facebook/react/pull/6570))
+- Stop incorrectly warning about using `onScroll` event handler with server rendering. ([@Aweary](https://github.com/Aweary) in [#6678](https://github.com/facebook/react/pull/6678))
+- Fix grammar in the controlled input warning. ([@jakeboone02](https://github.com/jakeboone02) in [#6657](https://github.com/facebook/react/pull/6657))
+- Fix issue preventing `<object>` nodes from being able to read `<param>` nodes in IE. ([@syranide](https://github.com/syranide) in [#6691](https://github.com/facebook/react/pull/6691))
+- Fix issue resulting in crash when using experimental error boundaries with server rendering. ([@jimfb](https://github.com/jimfb) in [#6694](https://github.com/facebook/react/pull/6694))
+- Add additional information to the controlled input warning. ([@borisyankov](https://github.com/borisyankov) in [#6341](https://github.com/facebook/react/pull/6341))
+
+### React Perf Add-on
+- Completely rewritten to collect data more accurately and to be easier to maintain. ([@gaearon](https://github.com/gaearon) in [#6647](https://github.com/facebook/react/pull/6647), [#6046](https://github.com/facebook/react/pull/6046))
+
+### React Native Renderer
+- Remove some special cases for platform specific branching. ([@sebmarkbage](https://github.com/sebmarkbage) in [#6660](https://github.com/facebook/react/pull/6660))
+- Remove use of `merge` utility. ([@sebmarkbage](https://github.com/sebmarkbage) in [#6634](https://github.com/facebook/react/pull/6634))
+- Renamed some modules to better indicate usage ([@javache](https://github.com/javache) in [#6643](https://github.com/facebook/react/pull/6643))
+
+
 ## 15.0.2 (April 29, 2016)
 
 ### React
diff --git a/examples/basic-commonjs/package.json b/examples/basic-commonjs/package.json
index 89490abdf9..e42eb80de4 100644
--- a/examples/basic-commonjs/package.json
+++ b/examples/basic-commonjs/package.json
@@ -6,11 +6,11 @@
   "dependencies": {
     "babel-preset-es2015": "^6.6.0",
     "babel-preset-react": "^6.5.0",
-    "babelify": "^7.2.0",
-    "browserify": "^11.0.1",
-    "react": "15.0.1",
-    "react-dom": "15.0.1",
-    "watchify": "^3.4.0"
+    "babelify": "^7.3.0",
+    "browserify": "^13.0.0",
+    "react": "^15.0.2",
+    "react-dom": "^15.0.2",
+    "watchify": "^3.7.0"
   },
   "scripts": {
     "build": "browserify ./index.js -t babelify -o bundle.js",
diff --git a/grunt/config/compress.js b/grunt/config/compress.js
index f225443776..020fe3d425 100644
--- a/grunt/config/compress.js
+++ b/grunt/config/compress.js
@@ -10,7 +10,7 @@ module.exports = {
       archive: './build/react-' + version + '.zip',
     },
     files: [
-      {cwd: './build/starter', src: ['**'], dest: 'react-' + version + '/'},
+      {cwd: './build/starter', src: ['**'], dot: true, dest: 'react-' + version + '/'},
     ],
   },
 };
diff --git a/grunt/tasks/jest.js b/grunt/tasks/jest.js
index da406e9111..fb8c1113ab 100644
--- a/grunt/tasks/jest.js
+++ b/grunt/tasks/jest.js
@@ -77,7 +77,7 @@ function writeTempConfig(callback) {
 function run(done, configPath) {
   grunt.log.writeln('running jest (this may take a while)');
 
-  var args = ['--harmony', path.join('node_modules', 'jest-cli', 'bin', 'jest')];
+  var args = ['--harmony', path.join('node_modules', 'jest-cli', 'bin', 'jest'), '--runInBand'];
   if (configPath) {
     args.push('--config', configPath);
   }
diff --git a/grunt/tasks/npm-react-addons.js b/grunt/tasks/npm-react-addons.js
index 948acebf1c..0f3d088d9c 100644
--- a/grunt/tasks/npm-react-addons.js
+++ b/grunt/tasks/npm-react-addons.js
@@ -16,7 +16,7 @@ var addons = {
     docs: 'two-way-binding-helpers',
   },
   Perf: {
-    module: 'ReactDefaultPerf',
+    module: 'ReactPerf',
     name: 'perf',
     docs: 'perf',
   },
diff --git a/gulpfile.js b/gulpfile.js
index 2c2a7c9823..c3db76382c 100644
--- a/gulpfile.js
+++ b/gulpfile.js
@@ -39,12 +39,7 @@ var whiteListNames = [
   'deepFreezeAndThrowOnMutationInDev',
   'flattenStyle',
   'InitializeJavaScriptAppEngine',
-  'InteractionManager',
-  'JSTimersExecution',
-  'merge',
-  'Platform',
   'RCTEventEmitter',
-  'RCTLog',
   'TextInputState',
   'UIManager',
   'View',
diff --git a/npm-shrinkwrap.json b/npm-shrinkwrap.json
index 3fc4f414a5..df73d752b8 100644
--- a/npm-shrinkwrap.json
+++ b/npm-shrinkwrap.json
@@ -1,6 +1,6 @@
 {
   "name": "react-build",
-  "version": "15.0.1",
+  "version": "15.0.3-alpha.1",
   "dependencies": {
     "async": {
       "version": "1.5.2",
@@ -13262,9 +13262,9 @@
       }
     },
     "jest-cli": {
-      "version": "0.9.2",
-      "from": "jest-cli@>=0.9.0 <0.10.0",
-      "resolved": "https://registry.npmjs.org/jest-cli/-/jest-cli-0.9.2.tgz",
+      "version": "12.0.2",
+      "from": "jest-cli@>=12.0.2 <13.0.0",
+      "resolved": "https://registry.npmjs.org/jest-cli/-/jest-cli-12.0.2.tgz",
       "dependencies": {
         "chalk": {
           "version": "1.1.3",
@@ -13352,9 +13352,9 @@
           "resolved": "https://registry.npmjs.org/diff/-/diff-2.2.2.tgz"
         },
         "graceful-fs": {
-          "version": "4.1.3",
+          "version": "4.1.4",
           "from": "graceful-fs@>=4.1.3 <5.0.0",
-          "resolved": "https://registry.npmjs.org/graceful-fs/-/graceful-fs-4.1.3.tgz"
+          "resolved": "https://registry.npmjs.org/graceful-fs/-/graceful-fs-4.1.4.tgz"
         },
         "istanbul": {
           "version": "0.4.3",
@@ -13443,14 +13443,14 @@
                   "resolved": "https://registry.npmjs.org/minimatch/-/minimatch-2.0.10.tgz",
                   "dependencies": {
                     "brace-expansion": {
-                      "version": "1.1.3",
+                      "version": "1.1.4",
                       "from": "brace-expansion@>=1.0.0 <2.0.0",
-                      "resolved": "https://registry.npmjs.org/brace-expansion/-/brace-expansion-1.1.3.tgz",
+                      "resolved": "https://registry.npmjs.org/brace-expansion/-/brace-expansion-1.1.4.tgz",
                       "dependencies": {
                         "balanced-match": {
-                          "version": "0.3.0",
-                          "from": "balanced-match@>=0.3.0 <0.4.0",
-                          "resolved": "https://registry.npmjs.org/balanced-match/-/balanced-match-0.3.0.tgz"
+                          "version": "0.4.1",
+                          "from": "balanced-match@>=0.4.1 <0.5.0",
+                          "resolved": "https://registry.npmjs.org/balanced-match/-/balanced-match-0.4.1.tgz"
                         },
                         "concat-map": {
                           "version": "0.0.1",
@@ -13512,13 +13512,13 @@
               }
             },
             "js-yaml": {
-              "version": "3.5.5",
+              "version": "3.6.0",
               "from": "js-yaml@>=3.0.0 <4.0.0",
-              "resolved": "https://registry.npmjs.org/js-yaml/-/js-yaml-3.5.5.tgz",
+              "resolved": "https://registry.npmjs.org/js-yaml/-/js-yaml-3.6.0.tgz",
               "dependencies": {
                 "argparse": {
                   "version": "1.0.7",
-                  "from": "argparse@>=1.0.2 <2.0.0",
+                  "from": "argparse@>=1.0.7 <2.0.0",
                   "resolved": "https://registry.npmjs.org/argparse/-/argparse-1.0.7.tgz",
                   "dependencies": {
                     "sprintf-js": {
@@ -13566,487 +13566,551 @@
             }
           }
         },
-        "jsdom": {
-          "version": "7.2.2",
-          "from": "jsdom@>=7.2.0 <8.0.0",
-          "resolved": "https://registry.npmjs.org/jsdom/-/jsdom-7.2.2.tgz",
+        "jest-environment-jsdom": {
+          "version": "12.0.2",
+          "from": "jest-environment-jsdom@>=12.0.2 <13.0.0",
+          "resolved": "https://registry.npmjs.org/jest-environment-jsdom/-/jest-environment-jsdom-12.0.2.tgz",
           "dependencies": {
-            "abab": {
-              "version": "1.0.3",
-              "from": "abab@>=1.0.0 <2.0.0",
-              "resolved": "https://registry.npmjs.org/abab/-/abab-1.0.3.tgz"
-            },
-            "acorn": {
-              "version": "2.7.0",
-              "from": "acorn@>=2.4.0 <3.0.0",
-              "resolved": "https://registry.npmjs.org/acorn/-/acorn-2.7.0.tgz"
-            },
-            "acorn-globals": {
-              "version": "1.0.9",
-              "from": "acorn-globals@>=1.0.4 <2.0.0",
-              "resolved": "https://registry.npmjs.org/acorn-globals/-/acorn-globals-1.0.9.tgz"
-            },
-            "cssom": {
-              "version": "0.3.1",
-              "from": "cssom@>=0.3.0 <0.4.0",
-              "resolved": "https://registry.npmjs.org/cssom/-/cssom-0.3.1.tgz"
-            },
-            "cssstyle": {
-              "version": "0.2.34",
-              "from": "cssstyle@>=0.2.29 <0.3.0",
-              "resolved": "https://registry.npmjs.org/cssstyle/-/cssstyle-0.2.34.tgz"
-            },
-            "escodegen": {
-              "version": "1.8.0",
-              "from": "escodegen@>=1.6.1 <2.0.0",
-              "resolved": "https://registry.npmjs.org/escodegen/-/escodegen-1.8.0.tgz",
+            "jsdom": {
+              "version": "8.5.0",
+              "from": "jsdom@>=8.4.1 <9.0.0",
+              "resolved": "https://registry.npmjs.org/jsdom/-/jsdom-8.5.0.tgz",
               "dependencies": {
-                "estraverse": {
-                  "version": "1.9.3",
-                  "from": "estraverse@>=1.9.1 <2.0.0",
-                  "resolved": "https://registry.npmjs.org/estraverse/-/estraverse-1.9.3.tgz"
+                "abab": {
+                  "version": "1.0.3",
+                  "from": "abab@>=1.0.0 <2.0.0",
+                  "resolved": "https://registry.npmjs.org/abab/-/abab-1.0.3.tgz"
                 },
-                "esutils": {
-                  "version": "2.0.2",
-                  "from": "esutils@>=2.0.2 <3.0.0",
-                  "resolved": "https://registry.npmjs.org/esutils/-/esutils-2.0.2.tgz"
+                "acorn": {
+                  "version": "2.7.0",
+                  "from": "acorn@>=2.4.0 <3.0.0",
+                  "resolved": "https://registry.npmjs.org/acorn/-/acorn-2.7.0.tgz"
                 },
-                "esprima": {
-                  "version": "2.7.2",
-                  "from": "esprima@>=2.7.1 <3.0.0",
-                  "resolved": "https://registry.npmjs.org/esprima/-/esprima-2.7.2.tgz"
+                "acorn-globals": {
+                  "version": "1.0.9",
+                  "from": "acorn-globals@>=1.0.4 <2.0.0",
+                  "resolved": "https://registry.npmjs.org/acorn-globals/-/acorn-globals-1.0.9.tgz"
                 },
-                "optionator": {
-                  "version": "0.8.1",
-                  "from": "optionator@>=0.8.1 <0.9.0",
-                  "resolved": "https://registry.npmjs.org/optionator/-/optionator-0.8.1.tgz",
+                "array-equal": {
+                  "version": "1.0.0",
+                  "from": "array-equal@>=1.0.0 <2.0.0",
+                  "resolved": "https://registry.npmjs.org/array-equal/-/array-equal-1.0.0.tgz"
+                },
+                "cssom": {
+                  "version": "0.3.1",
+                  "from": "cssom@>=0.3.0 <0.4.0",
+                  "resolved": "https://registry.npmjs.org/cssom/-/cssom-0.3.1.tgz"
+                },
+                "cssstyle": {
+                  "version": "0.2.34",
+                  "from": "cssstyle@>=0.2.34 <0.3.0",
+                  "resolved": "https://registry.npmjs.org/cssstyle/-/cssstyle-0.2.34.tgz"
+                },
+                "escodegen": {
+                  "version": "1.8.0",
+                  "from": "escodegen@>=1.6.1 <2.0.0",
+                  "resolved": "https://registry.npmjs.org/escodegen/-/escodegen-1.8.0.tgz",
                   "dependencies": {
-                    "prelude-ls": {
-                      "version": "1.1.2",
-                      "from": "prelude-ls@>=1.1.2 <1.2.0",
-                      "resolved": "https://registry.npmjs.org/prelude-ls/-/prelude-ls-1.1.2.tgz"
+                    "estraverse": {
+                      "version": "1.9.3",
+                      "from": "estraverse@>=1.9.1 <2.0.0",
+                      "resolved": "https://registry.npmjs.org/estraverse/-/estraverse-1.9.3.tgz"
                     },
-                    "deep-is": {
-                      "version": "0.1.3",
-                      "from": "deep-is@>=0.1.3 <0.2.0",
-                      "resolved": "https://registry.npmjs.org/deep-is/-/deep-is-0.1.3.tgz"
+                    "esutils": {
+                      "version": "2.0.2",
+                      "from": "esutils@>=2.0.2 <3.0.0",
+                      "resolved": "https://registry.npmjs.org/esutils/-/esutils-2.0.2.tgz"
                     },
-                    "wordwrap": {
-                      "version": "1.0.0",
-                      "from": "wordwrap@>=1.0.0 <1.1.0",
-                      "resolved": "https://registry.npmjs.org/wordwrap/-/wordwrap-1.0.0.tgz"
+                    "esprima": {
+                      "version": "2.7.2",
+                      "from": "esprima@>=2.7.1 <3.0.0",
+                      "resolved": "https://registry.npmjs.org/esprima/-/esprima-2.7.2.tgz"
                     },
-                    "type-check": {
-                      "version": "0.3.2",
-                      "from": "type-check@>=0.3.2 <0.4.0",
-                      "resolved": "https://registry.npmjs.org/type-check/-/type-check-0.3.2.tgz"
-                    },
-                    "levn": {
-                      "version": "0.3.0",
-                      "from": "levn@>=0.3.0 <0.4.0",
-                      "resolved": "https://registry.npmjs.org/levn/-/levn-0.3.0.tgz"
-                    },
-                    "fast-levenshtein": {
-                      "version": "1.1.3",
-                      "from": "fast-levenshtein@>=1.1.0 <2.0.0",
-                      "resolved": "https://registry.npmjs.org/fast-levenshtein/-/fast-levenshtein-1.1.3.tgz"
-                    }
-                  }
-                },
-                "source-map": {
-                  "version": "0.2.0",
-                  "from": "source-map@>=0.2.0 <0.3.0",
-                  "resolved": "https://registry.npmjs.org/source-map/-/source-map-0.2.0.tgz",
-                  "dependencies": {
-                    "amdefine": {
-                      "version": "1.0.0",
-                      "from": "amdefine@>=0.0.4",
-                      "resolved": "https://registry.npmjs.org/amdefine/-/amdefine-1.0.0.tgz"
-                    }
-                  }
-                }
-              }
-            },
-            "nwmatcher": {
-              "version": "1.3.7",
-              "from": "nwmatcher@>=1.3.7 <2.0.0",
-              "resolved": "https://registry.npmjs.org/nwmatcher/-/nwmatcher-1.3.7.tgz"
-            },
-            "parse5": {
-              "version": "1.5.1",
-              "from": "parse5@>=1.5.1 <2.0.0",
-              "resolved": "https://registry.npmjs.org/parse5/-/parse5-1.5.1.tgz"
-            },
-            "request": {
-              "version": "2.70.0",
-              "from": "request@>=2.55.0 <3.0.0",
-              "resolved": "https://registry.npmjs.org/request/-/request-2.70.0.tgz",
-              "dependencies": {
-                "aws-sign2": {
-                  "version": "0.6.0",
-                  "from": "aws-sign2@>=0.6.0 <0.7.0",
-                  "resolved": "https://registry.npmjs.org/aws-sign2/-/aws-sign2-0.6.0.tgz"
-                },
-                "aws4": {
-                  "version": "1.3.2",
-                  "from": "aws4@>=1.2.1 <2.0.0",
-                  "resolved": "https://registry.npmjs.org/aws4/-/aws4-1.3.2.tgz",
-                  "dependencies": {
-                    "lru-cache": {
-                      "version": "4.0.1",
-                      "from": "lru-cache@>=4.0.0 <5.0.0",
-                      "resolved": "https://registry.npmjs.org/lru-cache/-/lru-cache-4.0.1.tgz",
+                    "optionator": {
+                      "version": "0.8.1",
+                      "from": "optionator@>=0.8.1 <0.9.0",
+                      "resolved": "https://registry.npmjs.org/optionator/-/optionator-0.8.1.tgz",
                       "dependencies": {
-                        "pseudomap": {
-                          "version": "1.0.2",
-                          "from": "pseudomap@>=1.0.1 <2.0.0",
-                          "resolved": "https://registry.npmjs.org/pseudomap/-/pseudomap-1.0.2.tgz"
+                        "prelude-ls": {
+                          "version": "1.1.2",
+                          "from": "prelude-ls@>=1.1.2 <1.2.0",
+                          "resolved": "https://registry.npmjs.org/prelude-ls/-/prelude-ls-1.1.2.tgz"
                         },
-                        "yallist": {
-                          "version": "2.0.0",
-                          "from": "yallist@>=2.0.0 <3.0.0",
-                          "resolved": "https://registry.npmjs.org/yallist/-/yallist-2.0.0.tgz"
-                        }
-                      }
-                    }
-                  }
-                },
-                "bl": {
-                  "version": "1.1.2",
-                  "from": "bl@>=1.1.2 <1.2.0",
-                  "resolved": "https://registry.npmjs.org/bl/-/bl-1.1.2.tgz",
-                  "dependencies": {
-                    "readable-stream": {
-                      "version": "2.0.6",
-                      "from": "readable-stream@>=2.0.5 <2.1.0",
-                      "resolved": "https://registry.npmjs.org/readable-stream/-/readable-stream-2.0.6.tgz",
-                      "dependencies": {
-                        "core-util-is": {
-                          "version": "1.0.2",
-                          "from": "core-util-is@>=1.0.0 <1.1.0",
-                          "resolved": "https://registry.npmjs.org/core-util-is/-/core-util-is-1.0.2.tgz"
+                        "deep-is": {
+                          "version": "0.1.3",
+                          "from": "deep-is@>=0.1.3 <0.2.0",
+                          "resolved": "https://registry.npmjs.org/deep-is/-/deep-is-0.1.3.tgz"
                         },
-                        "inherits": {
-                          "version": "2.0.1",
-                          "from": "inherits@>=2.0.1 <2.1.0",
-                          "resolved": "https://registry.npmjs.org/inherits/-/inherits-2.0.1.tgz"
-                        },
-                        "isarray": {
+                        "wordwrap": {
                           "version": "1.0.0",
-                          "from": "isarray@>=1.0.0 <1.1.0",
-                          "resolved": "https://registry.npmjs.org/isarray/-/isarray-1.0.0.tgz"
+                          "from": "wordwrap@>=1.0.0 <1.1.0",
+                          "resolved": "https://registry.npmjs.org/wordwrap/-/wordwrap-1.0.0.tgz"
                         },
-                        "process-nextick-args": {
-                          "version": "1.0.6",
-                          "from": "process-nextick-args@>=1.0.6 <1.1.0",
-                          "resolved": "https://registry.npmjs.org/process-nextick-args/-/process-nextick-args-1.0.6.tgz"
+                        "type-check": {
+                          "version": "0.3.2",
+                          "from": "type-check@>=0.3.2 <0.4.0",
+                          "resolved": "https://registry.npmjs.org/type-check/-/type-check-0.3.2.tgz"
                         },
-                        "string_decoder": {
-                          "version": "0.10.31",
-                          "from": "string_decoder@>=0.10.0 <0.11.0",
-                          "resolved": "https://registry.npmjs.org/string_decoder/-/string_decoder-0.10.31.tgz"
+                        "levn": {
+                          "version": "0.3.0",
+                          "from": "levn@>=0.3.0 <0.4.0",
+                          "resolved": "https://registry.npmjs.org/levn/-/levn-0.3.0.tgz"
                         },
-                        "util-deprecate": {
-                          "version": "1.0.2",
-                          "from": "util-deprecate@>=1.0.1 <1.1.0",
-                          "resolved": "https://registry.npmjs.org/util-deprecate/-/util-deprecate-1.0.2.tgz"
-                        }
-                      }
-                    }
-                  }
-                },
-                "caseless": {
-                  "version": "0.11.0",
-                  "from": "caseless@>=0.11.0 <0.12.0",
-                  "resolved": "https://registry.npmjs.org/caseless/-/caseless-0.11.0.tgz"
-                },
-                "combined-stream": {
-                  "version": "1.0.5",
-                  "from": "combined-stream@>=1.0.5 <1.1.0",
-                  "resolved": "https://registry.npmjs.org/combined-stream/-/combined-stream-1.0.5.tgz",
-                  "dependencies": {
-                    "delayed-stream": {
-                      "version": "1.0.0",
-                      "from": "delayed-stream@>=1.0.0 <1.1.0",
-                      "resolved": "https://registry.npmjs.org/delayed-stream/-/delayed-stream-1.0.0.tgz"
-                    }
-                  }
-                },
-                "extend": {
-                  "version": "3.0.0",
-                  "from": "extend@>=3.0.0 <3.1.0",
-                  "resolved": "https://registry.npmjs.org/extend/-/extend-3.0.0.tgz"
-                },
-                "forever-agent": {
-                  "version": "0.6.1",
-                  "from": "forever-agent@>=0.6.1 <0.7.0",
-                  "resolved": "https://registry.npmjs.org/forever-agent/-/forever-agent-0.6.1.tgz"
-                },
-                "form-data": {
-                  "version": "1.0.0-rc4",
-                  "from": "form-data@>=1.0.0-rc3 <1.1.0",
-                  "resolved": "https://registry.npmjs.org/form-data/-/form-data-1.0.0-rc4.tgz"
-                },
-                "har-validator": {
-                  "version": "2.0.6",
-                  "from": "har-validator@>=2.0.6 <2.1.0",
-                  "resolved": "https://registry.npmjs.org/har-validator/-/har-validator-2.0.6.tgz",
-                  "dependencies": {
-                    "commander": {
-                      "version": "2.9.0",
-                      "from": "commander@>=2.9.0 <3.0.0",
-                      "resolved": "https://registry.npmjs.org/commander/-/commander-2.9.0.tgz",
-                      "dependencies": {
-                        "graceful-readlink": {
-                          "version": "1.0.1",
-                          "from": "graceful-readlink@>=1.0.0",
-                          "resolved": "https://registry.npmjs.org/graceful-readlink/-/graceful-readlink-1.0.1.tgz"
+                        "fast-levenshtein": {
+                          "version": "1.1.3",
+                          "from": "fast-levenshtein@>=1.1.0 <2.0.0",
+                          "resolved": "https://registry.npmjs.org/fast-levenshtein/-/fast-levenshtein-1.1.3.tgz"
                         }
                       }
                     },
-                    "is-my-json-valid": {
-                      "version": "2.13.1",
-                      "from": "is-my-json-valid@>=2.12.4 <3.0.0",
-                      "resolved": "https://registry.npmjs.org/is-my-json-valid/-/is-my-json-valid-2.13.1.tgz",
+                    "source-map": {
+                      "version": "0.2.0",
+                      "from": "source-map@>=0.2.0 <0.3.0",
+                      "resolved": "https://registry.npmjs.org/source-map/-/source-map-0.2.0.tgz",
                       "dependencies": {
-                        "generate-function": {
-                          "version": "2.0.0",
-                          "from": "generate-function@>=2.0.0 <3.0.0",
-                          "resolved": "https://registry.npmjs.org/generate-function/-/generate-function-2.0.0.tgz"
-                        },
-                        "generate-object-property": {
-                          "version": "1.2.0",
-                          "from": "generate-object-property@>=1.1.0 <2.0.0",
-                          "resolved": "https://registry.npmjs.org/generate-object-property/-/generate-object-property-1.2.0.tgz",
+                        "amdefine": {
+                          "version": "1.0.0",
+                          "from": "amdefine@>=0.0.4",
+                          "resolved": "https://registry.npmjs.org/amdefine/-/amdefine-1.0.0.tgz"
+                        }
+                      }
+                    }
+                  }
+                },
+                "iconv-lite": {
+                  "version": "0.4.13",
+                  "from": "iconv-lite@>=0.4.13 <0.5.0",
+                  "resolved": "https://registry.npmjs.org/iconv-lite/-/iconv-lite-0.4.13.tgz"
+                },
+                "nwmatcher": {
+                  "version": "1.3.7",
+                  "from": "nwmatcher@>=1.3.7 <2.0.0",
+                  "resolved": "https://registry.npmjs.org/nwmatcher/-/nwmatcher-1.3.7.tgz"
+                },
+                "parse5": {
+                  "version": "1.5.1",
+                  "from": "parse5@>=1.5.1 <2.0.0",
+                  "resolved": "https://registry.npmjs.org/parse5/-/parse5-1.5.1.tgz"
+                },
+                "request": {
+                  "version": "2.72.0",
+                  "from": "request@>=2.55.0 <3.0.0",
+                  "resolved": "https://registry.npmjs.org/request/-/request-2.72.0.tgz",
+                  "dependencies": {
+                    "aws-sign2": {
+                      "version": "0.6.0",
+                      "from": "aws-sign2@>=0.6.0 <0.7.0",
+                      "resolved": "https://registry.npmjs.org/aws-sign2/-/aws-sign2-0.6.0.tgz"
+                    },
+                    "aws4": {
+                      "version": "1.4.1",
+                      "from": "aws4@>=1.2.1 <2.0.0",
+                      "resolved": "https://registry.npmjs.org/aws4/-/aws4-1.4.1.tgz"
+                    },
+                    "bl": {
+                      "version": "1.1.2",
+                      "from": "bl@>=1.1.2 <1.2.0",
+                      "resolved": "https://registry.npmjs.org/bl/-/bl-1.1.2.tgz",
+                      "dependencies": {
+                        "readable-stream": {
+                          "version": "2.0.6",
+                          "from": "readable-stream@>=2.0.5 <2.1.0",
+                          "resolved": "https://registry.npmjs.org/readable-stream/-/readable-stream-2.0.6.tgz",
                           "dependencies": {
-                            "is-property": {
+                            "core-util-is": {
                               "version": "1.0.2",
-                              "from": "is-property@>=1.0.0 <2.0.0",
-                              "resolved": "https://registry.npmjs.org/is-property/-/is-property-1.0.2.tgz"
+                              "from": "core-util-is@>=1.0.0 <1.1.0",
+                              "resolved": "https://registry.npmjs.org/core-util-is/-/core-util-is-1.0.2.tgz"
+                            },
+                            "inherits": {
+                              "version": "2.0.1",
+                              "from": "inherits@>=2.0.1 <2.1.0",
+                              "resolved": "https://registry.npmjs.org/inherits/-/inherits-2.0.1.tgz"
+                            },
+                            "isarray": {
+                              "version": "1.0.0",
+                              "from": "isarray@>=1.0.0 <1.1.0",
+                              "resolved": "https://registry.npmjs.org/isarray/-/isarray-1.0.0.tgz"
+                            },
+                            "process-nextick-args": {
+                              "version": "1.0.7",
+                              "from": "process-nextick-args@>=1.0.6 <1.1.0",
+                              "resolved": "https://registry.npmjs.org/process-nextick-args/-/process-nextick-args-1.0.7.tgz"
+                            },
+                            "string_decoder": {
+                              "version": "0.10.31",
+                              "from": "string_decoder@>=0.10.0 <0.11.0",
+                              "resolved": "https://registry.npmjs.org/string_decoder/-/string_decoder-0.10.31.tgz"
+                            },
+                            "util-deprecate": {
+                              "version": "1.0.2",
+                              "from": "util-deprecate@>=1.0.1 <1.1.0",
+                              "resolved": "https://registry.npmjs.org/util-deprecate/-/util-deprecate-1.0.2.tgz"
+                            }
+                          }
+                        }
+                      }
+                    },
+                    "caseless": {
+                      "version": "0.11.0",
+                      "from": "caseless@>=0.11.0 <0.12.0",
+                      "resolved": "https://registry.npmjs.org/caseless/-/caseless-0.11.0.tgz"
+                    },
+                    "combined-stream": {
+                      "version": "1.0.5",
+                      "from": "combined-stream@>=1.0.5 <1.1.0",
+                      "resolved": "https://registry.npmjs.org/combined-stream/-/combined-stream-1.0.5.tgz",
+                      "dependencies": {
+                        "delayed-stream": {
+                          "version": "1.0.0",
+                          "from": "delayed-stream@>=1.0.0 <1.1.0",
+                          "resolved": "https://registry.npmjs.org/delayed-stream/-/delayed-stream-1.0.0.tgz"
+                        }
+                      }
+                    },
+                    "extend": {
+                      "version": "3.0.0",
+                      "from": "extend@>=3.0.0 <3.1.0",
+                      "resolved": "https://registry.npmjs.org/extend/-/extend-3.0.0.tgz"
+                    },
+                    "forever-agent": {
+                      "version": "0.6.1",
+                      "from": "forever-agent@>=0.6.1 <0.7.0",
+                      "resolved": "https://registry.npmjs.org/forever-agent/-/forever-agent-0.6.1.tgz"
+                    },
+                    "form-data": {
+                      "version": "1.0.0-rc4",
+                      "from": "form-data@>=1.0.0-rc3 <1.1.0",
+                      "resolved": "https://registry.npmjs.org/form-data/-/form-data-1.0.0-rc4.tgz"
+                    },
+                    "har-validator": {
+                      "version": "2.0.6",
+                      "from": "har-validator@>=2.0.6 <2.1.0",
+                      "resolved": "https://registry.npmjs.org/har-validator/-/har-validator-2.0.6.tgz",
+                      "dependencies": {
+                        "commander": {
+                          "version": "2.9.0",
+                          "from": "commander@>=2.9.0 <3.0.0",
+                          "resolved": "https://registry.npmjs.org/commander/-/commander-2.9.0.tgz",
+                          "dependencies": {
+                            "graceful-readlink": {
+                              "version": "1.0.1",
+                              "from": "graceful-readlink@>=1.0.0",
+                              "resolved": "https://registry.npmjs.org/graceful-readlink/-/graceful-readlink-1.0.1.tgz"
                             }
                           }
                         },
-                        "jsonpointer": {
-                          "version": "2.0.0",
-                          "from": "jsonpointer@2.0.0",
-                          "resolved": "https://registry.npmjs.org/jsonpointer/-/jsonpointer-2.0.0.tgz"
-                        },
-                        "xtend": {
-                          "version": "4.0.1",
-                          "from": "xtend@>=4.0.0 <5.0.0",
-                          "resolved": "https://registry.npmjs.org/xtend/-/xtend-4.0.1.tgz"
-                        }
-                      }
-                    },
-                    "pinkie-promise": {
-                      "version": "2.0.0",
-                      "from": "pinkie-promise@>=2.0.0 <3.0.0",
-                      "resolved": "https://registry.npmjs.org/pinkie-promise/-/pinkie-promise-2.0.0.tgz",
-                      "dependencies": {
-                        "pinkie": {
-                          "version": "2.0.4",
-                          "from": "pinkie@>=2.0.0 <3.0.0",
-                          "resolved": "https://registry.npmjs.org/pinkie/-/pinkie-2.0.4.tgz"
-                        }
-                      }
-                    }
-                  }
-                },
-                "hawk": {
-                  "version": "3.1.3",
-                  "from": "hawk@>=3.1.3 <3.2.0",
-                  "resolved": "https://registry.npmjs.org/hawk/-/hawk-3.1.3.tgz",
-                  "dependencies": {
-                    "hoek": {
-                      "version": "2.16.3",
-                      "from": "hoek@>=2.0.0 <3.0.0",
-                      "resolved": "https://registry.npmjs.org/hoek/-/hoek-2.16.3.tgz"
-                    },
-                    "boom": {
-                      "version": "2.10.1",
-                      "from": "boom@>=2.0.0 <3.0.0",
-                      "resolved": "https://registry.npmjs.org/boom/-/boom-2.10.1.tgz"
-                    },
-                    "cryptiles": {
-                      "version": "2.0.5",
-                      "from": "cryptiles@>=2.0.0 <3.0.0",
-                      "resolved": "https://registry.npmjs.org/cryptiles/-/cryptiles-2.0.5.tgz"
-                    },
-                    "sntp": {
-                      "version": "1.0.9",
-                      "from": "sntp@>=1.0.0 <2.0.0",
-                      "resolved": "https://registry.npmjs.org/sntp/-/sntp-1.0.9.tgz"
-                    }
-                  }
-                },
-                "http-signature": {
-                  "version": "1.1.1",
-                  "from": "http-signature@>=1.1.0 <1.2.0",
-                  "resolved": "https://registry.npmjs.org/http-signature/-/http-signature-1.1.1.tgz",
-                  "dependencies": {
-                    "assert-plus": {
-                      "version": "0.2.0",
-                      "from": "assert-plus@>=0.2.0 <0.3.0",
-                      "resolved": "https://registry.npmjs.org/assert-plus/-/assert-plus-0.2.0.tgz"
-                    },
-                    "jsprim": {
-                      "version": "1.2.2",
-                      "from": "jsprim@>=1.2.2 <2.0.0",
-                      "resolved": "https://registry.npmjs.org/jsprim/-/jsprim-1.2.2.tgz",
-                      "dependencies": {
-                        "extsprintf": {
-                          "version": "1.0.2",
-                          "from": "extsprintf@1.0.2",
-                          "resolved": "https://registry.npmjs.org/extsprintf/-/extsprintf-1.0.2.tgz"
-                        },
-                        "json-schema": {
-                          "version": "0.2.2",
-                          "from": "json-schema@0.2.2",
-                          "resolved": "https://registry.npmjs.org/json-schema/-/json-schema-0.2.2.tgz"
-                        },
-                        "verror": {
-                          "version": "1.3.6",
-                          "from": "verror@1.3.6",
-                          "resolved": "https://registry.npmjs.org/verror/-/verror-1.3.6.tgz"
-                        }
-                      }
-                    },
-                    "sshpk": {
-                      "version": "1.7.4",
-                      "from": "sshpk@>=1.7.0 <2.0.0",
-                      "resolved": "https://registry.npmjs.org/sshpk/-/sshpk-1.7.4.tgz",
-                      "dependencies": {
-                        "asn1": {
-                          "version": "0.2.3",
-                          "from": "asn1@>=0.2.3 <0.3.0",
-                          "resolved": "https://registry.npmjs.org/asn1/-/asn1-0.2.3.tgz"
-                        },
-                        "dashdash": {
-                          "version": "1.13.0",
-                          "from": "dashdash@>=1.10.1 <2.0.0",
-                          "resolved": "https://registry.npmjs.org/dashdash/-/dashdash-1.13.0.tgz",
+                        "is-my-json-valid": {
+                          "version": "2.13.1",
+                          "from": "is-my-json-valid@>=2.12.4 <3.0.0",
+                          "resolved": "https://registry.npmjs.org/is-my-json-valid/-/is-my-json-valid-2.13.1.tgz",
                           "dependencies": {
+                            "generate-function": {
+                              "version": "2.0.0",
+                              "from": "generate-function@>=2.0.0 <3.0.0",
+                              "resolved": "https://registry.npmjs.org/generate-function/-/generate-function-2.0.0.tgz"
+                            },
+                            "generate-object-property": {
+                              "version": "1.2.0",
+                              "from": "generate-object-property@>=1.1.0 <2.0.0",
+                              "resolved": "https://registry.npmjs.org/generate-object-property/-/generate-object-property-1.2.0.tgz",
+                              "dependencies": {
+                                "is-property": {
+                                  "version": "1.0.2",
+                                  "from": "is-property@>=1.0.0 <2.0.0",
+                                  "resolved": "https://registry.npmjs.org/is-property/-/is-property-1.0.2.tgz"
+                                }
+                              }
+                            },
+                            "jsonpointer": {
+                              "version": "2.0.0",
+                              "from": "jsonpointer@2.0.0",
+                              "resolved": "https://registry.npmjs.org/jsonpointer/-/jsonpointer-2.0.0.tgz"
+                            },
+                            "xtend": {
+                              "version": "4.0.1",
+                              "from": "xtend@>=4.0.0 <5.0.0",
+                              "resolved": "https://registry.npmjs.org/xtend/-/xtend-4.0.1.tgz"
+                            }
+                          }
+                        },
+                        "pinkie-promise": {
+                          "version": "2.0.1",
+                          "from": "pinkie-promise@>=2.0.0 <3.0.0",
+                          "resolved": "https://registry.npmjs.org/pinkie-promise/-/pinkie-promise-2.0.1.tgz",
+                          "dependencies": {
+                            "pinkie": {
+                              "version": "2.0.4",
+                              "from": "pinkie@>=2.0.0 <3.0.0",
+                              "resolved": "https://registry.npmjs.org/pinkie/-/pinkie-2.0.4.tgz"
+                            }
+                          }
+                        }
+                      }
+                    },
+                    "hawk": {
+                      "version": "3.1.3",
+                      "from": "hawk@>=3.1.3 <3.2.0",
+                      "resolved": "https://registry.npmjs.org/hawk/-/hawk-3.1.3.tgz",
+                      "dependencies": {
+                        "hoek": {
+                          "version": "2.16.3",
+                          "from": "hoek@>=2.0.0 <3.0.0",
+                          "resolved": "https://registry.npmjs.org/hoek/-/hoek-2.16.3.tgz"
+                        },
+                        "boom": {
+                          "version": "2.10.1",
+                          "from": "boom@>=2.0.0 <3.0.0",
+                          "resolved": "https://registry.npmjs.org/boom/-/boom-2.10.1.tgz"
+                        },
+                        "cryptiles": {
+                          "version": "2.0.5",
+                          "from": "cryptiles@>=2.0.0 <3.0.0",
+                          "resolved": "https://registry.npmjs.org/cryptiles/-/cryptiles-2.0.5.tgz"
+                        },
+                        "sntp": {
+                          "version": "1.0.9",
+                          "from": "sntp@>=1.0.0 <2.0.0",
+                          "resolved": "https://registry.npmjs.org/sntp/-/sntp-1.0.9.tgz"
+                        }
+                      }
+                    },
+                    "http-signature": {
+                      "version": "1.1.1",
+                      "from": "http-signature@>=1.1.0 <1.2.0",
+                      "resolved": "https://registry.npmjs.org/http-signature/-/http-signature-1.1.1.tgz",
+                      "dependencies": {
+                        "assert-plus": {
+                          "version": "0.2.0",
+                          "from": "assert-plus@>=0.2.0 <0.3.0",
+                          "resolved": "https://registry.npmjs.org/assert-plus/-/assert-plus-0.2.0.tgz"
+                        },
+                        "jsprim": {
+                          "version": "1.2.2",
+                          "from": "jsprim@>=1.2.2 <2.0.0",
+                          "resolved": "https://registry.npmjs.org/jsprim/-/jsprim-1.2.2.tgz",
+                          "dependencies": {
+                            "extsprintf": {
+                              "version": "1.0.2",
+                              "from": "extsprintf@1.0.2",
+                              "resolved": "https://registry.npmjs.org/extsprintf/-/extsprintf-1.0.2.tgz"
+                            },
+                            "json-schema": {
+                              "version": "0.2.2",
+                              "from": "json-schema@0.2.2",
+                              "resolved": "https://registry.npmjs.org/json-schema/-/json-schema-0.2.2.tgz"
+                            },
+                            "verror": {
+                              "version": "1.3.6",
+                              "from": "verror@1.3.6",
+                              "resolved": "https://registry.npmjs.org/verror/-/verror-1.3.6.tgz"
+                            }
+                          }
+                        },
+                        "sshpk": {
+                          "version": "1.8.3",
+                          "from": "sshpk@>=1.7.0 <2.0.0",
+                          "resolved": "https://registry.npmjs.org/sshpk/-/sshpk-1.8.3.tgz",
+                          "dependencies": {
+                            "asn1": {
+                              "version": "0.2.3",
+                              "from": "asn1@>=0.2.3 <0.3.0",
+                              "resolved": "https://registry.npmjs.org/asn1/-/asn1-0.2.3.tgz"
+                            },
                             "assert-plus": {
                               "version": "1.0.0",
                               "from": "assert-plus@>=1.0.0 <2.0.0",
                               "resolved": "https://registry.npmjs.org/assert-plus/-/assert-plus-1.0.0.tgz"
+                            },
+                            "dashdash": {
+                              "version": "1.13.1",
+                              "from": "dashdash@>=1.12.0 <2.0.0",
+                              "resolved": "https://registry.npmjs.org/dashdash/-/dashdash-1.13.1.tgz"
+                            },
+                            "getpass": {
+                              "version": "0.1.6",
+                              "from": "getpass@>=0.1.1 <0.2.0",
+                              "resolved": "https://registry.npmjs.org/getpass/-/getpass-0.1.6.tgz"
+                            },
+                            "jsbn": {
+                              "version": "0.1.0",
+                              "from": "jsbn@>=0.1.0 <0.2.0",
+                              "resolved": "https://registry.npmjs.org/jsbn/-/jsbn-0.1.0.tgz"
+                            },
+                            "tweetnacl": {
+                              "version": "0.13.3",
+                              "from": "tweetnacl@>=0.13.0 <0.14.0",
+                              "resolved": "https://registry.npmjs.org/tweetnacl/-/tweetnacl-0.13.3.tgz"
+                            },
+                            "jodid25519": {
+                              "version": "1.0.2",
+                              "from": "jodid25519@>=1.0.0 <2.0.0",
+                              "resolved": "https://registry.npmjs.org/jodid25519/-/jodid25519-1.0.2.tgz"
+                            },
+                            "ecc-jsbn": {
+                              "version": "0.1.1",
+                              "from": "ecc-jsbn@>=0.1.1 <0.2.0",
+                              "resolved": "https://registry.npmjs.org/ecc-jsbn/-/ecc-jsbn-0.1.1.tgz"
                             }
                           }
-                        },
-                        "jsbn": {
-                          "version": "0.1.0",
-                          "from": "jsbn@>=0.1.0 <0.2.0",
-                          "resolved": "https://registry.npmjs.org/jsbn/-/jsbn-0.1.0.tgz"
-                        },
-                        "tweetnacl": {
-                          "version": "0.14.3",
-                          "from": "tweetnacl@>=0.13.0 <1.0.0",
-                          "resolved": "https://registry.npmjs.org/tweetnacl/-/tweetnacl-0.14.3.tgz"
-                        },
-                        "jodid25519": {
-                          "version": "1.0.2",
-                          "from": "jodid25519@>=1.0.0 <2.0.0",
-                          "resolved": "https://registry.npmjs.org/jodid25519/-/jodid25519-1.0.2.tgz"
-                        },
-                        "ecc-jsbn": {
-                          "version": "0.1.1",
-                          "from": "ecc-jsbn@>=0.0.1 <1.0.0",
-                          "resolved": "https://registry.npmjs.org/ecc-jsbn/-/ecc-jsbn-0.1.1.tgz"
                         }
                       }
+                    },
+                    "is-typedarray": {
+                      "version": "1.0.0",
+                      "from": "is-typedarray@>=1.0.0 <1.1.0",
+                      "resolved": "https://registry.npmjs.org/is-typedarray/-/is-typedarray-1.0.0.tgz"
+                    },
+                    "isstream": {
+                      "version": "0.1.2",
+                      "from": "isstream@>=0.1.2 <0.2.0",
+                      "resolved": "https://registry.npmjs.org/isstream/-/isstream-0.1.2.tgz"
+                    },
+                    "json-stringify-safe": {
+                      "version": "5.0.1",
+                      "from": "json-stringify-safe@>=5.0.1 <5.1.0",
+                      "resolved": "https://registry.npmjs.org/json-stringify-safe/-/json-stringify-safe-5.0.1.tgz"
+                    },
+                    "mime-types": {
+                      "version": "2.1.11",
+                      "from": "mime-types@>=2.1.7 <2.2.0",
+                      "resolved": "https://registry.npmjs.org/mime-types/-/mime-types-2.1.11.tgz",
+                      "dependencies": {
+                        "mime-db": {
+                          "version": "1.23.0",
+                          "from": "mime-db@>=1.23.0 <1.24.0",
+                          "resolved": "https://registry.npmjs.org/mime-db/-/mime-db-1.23.0.tgz"
+                        }
+                      }
+                    },
+                    "node-uuid": {
+                      "version": "1.4.7",
+                      "from": "node-uuid@>=1.4.7 <1.5.0",
+                      "resolved": "https://registry.npmjs.org/node-uuid/-/node-uuid-1.4.7.tgz"
+                    },
+                    "oauth-sign": {
+                      "version": "0.8.2",
+                      "from": "oauth-sign@>=0.8.1 <0.9.0",
+                      "resolved": "https://registry.npmjs.org/oauth-sign/-/oauth-sign-0.8.2.tgz"
+                    },
+                    "qs": {
+                      "version": "6.1.0",
+                      "from": "qs@>=6.1.0 <6.2.0",
+                      "resolved": "https://registry.npmjs.org/qs/-/qs-6.1.0.tgz"
+                    },
+                    "stringstream": {
+                      "version": "0.0.5",
+                      "from": "stringstream@>=0.0.4 <0.1.0",
+                      "resolved": "https://registry.npmjs.org/stringstream/-/stringstream-0.0.5.tgz"
+                    },
+                    "tunnel-agent": {
+                      "version": "0.4.3",
+                      "from": "tunnel-agent@>=0.4.1 <0.5.0",
+                      "resolved": "https://registry.npmjs.org/tunnel-agent/-/tunnel-agent-0.4.3.tgz"
                     }
                   }
                 },
-                "is-typedarray": {
-                  "version": "1.0.0",
-                  "from": "is-typedarray@>=1.0.0 <1.1.0",
-                  "resolved": "https://registry.npmjs.org/is-typedarray/-/is-typedarray-1.0.0.tgz"
+                "sax": {
+                  "version": "1.2.1",
+                  "from": "sax@>=1.1.4 <2.0.0",
+                  "resolved": "https://registry.npmjs.org/sax/-/sax-1.2.1.tgz"
                 },
-                "isstream": {
-                  "version": "0.1.2",
-                  "from": "isstream@>=0.1.2 <0.2.0",
-                  "resolved": "https://registry.npmjs.org/isstream/-/isstream-0.1.2.tgz"
+                "symbol-tree": {
+                  "version": "3.1.4",
+                  "from": "symbol-tree@>=3.1.0 <4.0.0",
+                  "resolved": "https://registry.npmjs.org/symbol-tree/-/symbol-tree-3.1.4.tgz"
                 },
-                "json-stringify-safe": {
-                  "version": "5.0.1",
-                  "from": "json-stringify-safe@>=5.0.1 <5.1.0",
-                  "resolved": "https://registry.npmjs.org/json-stringify-safe/-/json-stringify-safe-5.0.1.tgz"
+                "tough-cookie": {
+                  "version": "2.2.2",
+                  "from": "tough-cookie@>=2.2.0 <3.0.0",
+                  "resolved": "https://registry.npmjs.org/tough-cookie/-/tough-cookie-2.2.2.tgz"
                 },
-                "mime-types": {
-                  "version": "2.1.10",
-                  "from": "mime-types@>=2.1.7 <2.2.0",
-                  "resolved": "https://registry.npmjs.org/mime-types/-/mime-types-2.1.10.tgz",
+                "webidl-conversions": {
+                  "version": "3.0.1",
+                  "from": "webidl-conversions@>=3.0.1 <4.0.0",
+                  "resolved": "https://registry.npmjs.org/webidl-conversions/-/webidl-conversions-3.0.1.tgz"
+                },
+                "whatwg-url": {
+                  "version": "2.0.1",
+                  "from": "whatwg-url@>=2.0.1 <3.0.0",
+                  "resolved": "https://registry.npmjs.org/whatwg-url/-/whatwg-url-2.0.1.tgz",
                   "dependencies": {
-                    "mime-db": {
-                      "version": "1.22.0",
-                      "from": "mime-db@>=1.22.0 <1.23.0",
-                      "resolved": "https://registry.npmjs.org/mime-db/-/mime-db-1.22.0.tgz"
+                    "tr46": {
+                      "version": "0.0.3",
+                      "from": "tr46@>=0.0.3 <0.1.0",
+                      "resolved": "https://registry.npmjs.org/tr46/-/tr46-0.0.3.tgz"
                     }
                   }
                 },
-                "node-uuid": {
-                  "version": "1.4.7",
-                  "from": "node-uuid@>=1.4.7 <1.5.0",
-                  "resolved": "https://registry.npmjs.org/node-uuid/-/node-uuid-1.4.7.tgz"
-                },
-                "oauth-sign": {
-                  "version": "0.8.1",
-                  "from": "oauth-sign@>=0.8.1 <0.9.0",
-                  "resolved": "https://registry.npmjs.org/oauth-sign/-/oauth-sign-0.8.1.tgz"
-                },
-                "qs": {
-                  "version": "6.1.0",
-                  "from": "qs@>=6.1.0 <6.2.0",
-                  "resolved": "https://registry.npmjs.org/qs/-/qs-6.1.0.tgz"
-                },
-                "stringstream": {
-                  "version": "0.0.5",
-                  "from": "stringstream@>=0.0.4 <0.1.0",
-                  "resolved": "https://registry.npmjs.org/stringstream/-/stringstream-0.0.5.tgz"
-                },
-                "tunnel-agent": {
-                  "version": "0.4.2",
-                  "from": "tunnel-agent@>=0.4.1 <0.5.0",
-                  "resolved": "https://registry.npmjs.org/tunnel-agent/-/tunnel-agent-0.4.2.tgz"
+                "xml-name-validator": {
+                  "version": "2.0.1",
+                  "from": "xml-name-validator@>=2.0.1 <3.0.0",
+                  "resolved": "https://registry.npmjs.org/xml-name-validator/-/xml-name-validator-2.0.1.tgz"
                 }
               }
-            },
-            "sax": {
+            }
+          }
+        },
+        "jest-environment-node": {
+          "version": "12.0.2",
+          "from": "jest-environment-node@>=12.0.2 <13.0.0",
+          "resolved": "https://registry.npmjs.org/jest-environment-node/-/jest-environment-node-12.0.2.tgz"
+        },
+        "jest-haste-map": {
+          "version": "12.0.2",
+          "from": "jest-haste-map@>=12.0.2 <13.0.0",
+          "resolved": "https://registry.npmjs.org/jest-haste-map/-/jest-haste-map-12.0.2.tgz",
+          "dependencies": {
+            "denodeify": {
               "version": "1.2.1",
-              "from": "sax@>=1.1.4 <2.0.0",
-              "resolved": "https://registry.npmjs.org/sax/-/sax-1.2.1.tgz"
+              "from": "denodeify@>=1.2.1 <2.0.0",
+              "resolved": "https://registry.npmjs.org/denodeify/-/denodeify-1.2.1.tgz"
             },
-            "symbol-tree": {
-              "version": "3.1.4",
-              "from": "symbol-tree@>=3.1.0 <4.0.0",
-              "resolved": "https://registry.npmjs.org/symbol-tree/-/symbol-tree-3.1.4.tgz"
-            },
-            "tough-cookie": {
-              "version": "2.2.2",
-              "from": "tough-cookie@>=2.2.0 <3.0.0",
-              "resolved": "https://registry.npmjs.org/tough-cookie/-/tough-cookie-2.2.2.tgz"
-            },
-            "webidl-conversions": {
-              "version": "2.0.1",
-              "from": "webidl-conversions@>=2.0.0 <3.0.0",
-              "resolved": "https://registry.npmjs.org/webidl-conversions/-/webidl-conversions-2.0.1.tgz"
-            },
-            "whatwg-url-compat": {
-              "version": "0.6.5",
-              "from": "whatwg-url-compat@>=0.6.5 <0.7.0",
-              "resolved": "https://registry.npmjs.org/whatwg-url-compat/-/whatwg-url-compat-0.6.5.tgz",
+            "fb-watchman": {
+              "version": "1.9.0",
+              "from": "fb-watchman@>=1.9.0 <2.0.0",
+              "resolved": "https://registry.npmjs.org/fb-watchman/-/fb-watchman-1.9.0.tgz",
               "dependencies": {
-                "tr46": {
-                  "version": "0.0.3",
-                  "from": "tr46@>=0.0.1 <0.1.0",
-                  "resolved": "https://registry.npmjs.org/tr46/-/tr46-0.0.3.tgz"
+                "bser": {
+                  "version": "1.0.2",
+                  "from": "bser@>=1.0.2 <2.0.0",
+                  "resolved": "https://registry.npmjs.org/bser/-/bser-1.0.2.tgz",
+                  "dependencies": {
+                    "node-int64": {
+                      "version": "0.4.0",
+                      "from": "node-int64@>=0.4.0 <0.5.0",
+                      "resolved": "https://registry.npmjs.org/node-int64/-/node-int64-0.4.0.tgz"
+                    }
+                  }
                 }
               }
-            },
-            "xml-name-validator": {
-              "version": "2.0.1",
-              "from": "xml-name-validator@>=2.0.1 <3.0.0",
-              "resolved": "https://registry.npmjs.org/xml-name-validator/-/xml-name-validator-2.0.1.tgz"
+            }
+          }
+        },
+        "jest-jasmine1": {
+          "version": "12.0.2",
+          "from": "jest-jasmine1@>=12.0.2 <13.0.0",
+          "resolved": "https://registry.npmjs.org/jest-jasmine1/-/jest-jasmine1-12.0.2.tgz"
+        },
+        "jest-jasmine2": {
+          "version": "12.0.2",
+          "from": "jest-jasmine2@>=12.0.2 <13.0.0",
+          "resolved": "https://registry.npmjs.org/jest-jasmine2/-/jest-jasmine2-12.0.2.tgz"
+        },
+        "jest-mock": {
+          "version": "12.0.2",
+          "from": "jest-mock@>=12.0.2 <13.0.0",
+          "resolved": "https://registry.npmjs.org/jest-mock/-/jest-mock-12.0.2.tgz"
+        },
+        "jest-util": {
+          "version": "12.0.2",
+          "from": "jest-util@>=12.0.2 <13.0.0",
+          "resolved": "https://registry.npmjs.org/jest-util/-/jest-util-12.0.2.tgz",
+          "dependencies": {
+            "jest-mock": {
+              "version": "11.0.0",
+              "from": "jest-mock@11.0.0",
+              "resolved": "https://registry.npmjs.org/jest-mock/-/jest-mock-11.0.0.tgz"
             }
           }
         },
@@ -14063,78 +14127,53 @@
           }
         },
         "lodash.template": {
-          "version": "3.6.2",
-          "from": "lodash.template@>=3.6.2 <4.0.0",
-          "resolved": "https://registry.npmjs.org/lodash.template/-/lodash.template-3.6.2.tgz",
+          "version": "4.2.4",
+          "from": "lodash.template@>=4.2.4 <5.0.0",
+          "resolved": "https://registry.npmjs.org/lodash.template/-/lodash.template-4.2.4.tgz",
           "dependencies": {
-            "lodash._basecopy": {
-              "version": "3.0.1",
-              "from": "lodash._basecopy@>=3.0.0 <4.0.0",
-              "resolved": "https://registry.npmjs.org/lodash._basecopy/-/lodash._basecopy-3.0.1.tgz"
-            },
-            "lodash._basetostring": {
-              "version": "3.0.1",
-              "from": "lodash._basetostring@>=3.0.0 <4.0.0",
-              "resolved": "https://registry.npmjs.org/lodash._basetostring/-/lodash._basetostring-3.0.1.tgz"
-            },
-            "lodash._basevalues": {
-              "version": "3.0.0",
-              "from": "lodash._basevalues@>=3.0.0 <4.0.0",
-              "resolved": "https://registry.npmjs.org/lodash._basevalues/-/lodash._basevalues-3.0.0.tgz"
-            },
-            "lodash._isiterateecall": {
-              "version": "3.0.9",
-              "from": "lodash._isiterateecall@>=3.0.0 <4.0.0",
-              "resolved": "https://registry.npmjs.org/lodash._isiterateecall/-/lodash._isiterateecall-3.0.9.tgz"
-            },
             "lodash._reinterpolate": {
               "version": "3.0.0",
-              "from": "lodash._reinterpolate@>=3.0.0 <4.0.0",
+              "from": "lodash._reinterpolate@>=3.0.0 <3.1.0",
               "resolved": "https://registry.npmjs.org/lodash._reinterpolate/-/lodash._reinterpolate-3.0.0.tgz"
             },
-            "lodash.escape": {
-              "version": "3.2.0",
-              "from": "lodash.escape@>=3.0.0 <4.0.0",
-              "resolved": "https://registry.npmjs.org/lodash.escape/-/lodash.escape-3.2.0.tgz",
+            "lodash.assigninwith": {
+              "version": "4.0.6",
+              "from": "lodash.assigninwith@>=4.0.0 <5.0.0",
+              "resolved": "https://registry.npmjs.org/lodash.assigninwith/-/lodash.assigninwith-4.0.6.tgz",
               "dependencies": {
-                "lodash._root": {
-                  "version": "3.0.1",
-                  "from": "lodash._root@>=3.0.0 <4.0.0",
-                  "resolved": "https://registry.npmjs.org/lodash._root/-/lodash._root-3.0.1.tgz"
+                "lodash.keysin": {
+                  "version": "4.1.3",
+                  "from": "lodash.keysin@>=4.0.0 <5.0.0",
+                  "resolved": "https://registry.npmjs.org/lodash.keysin/-/lodash.keysin-4.1.3.tgz"
                 }
               }
             },
             "lodash.keys": {
-              "version": "3.1.2",
-              "from": "lodash.keys@>=3.0.0 <4.0.0",
-              "resolved": "https://registry.npmjs.org/lodash.keys/-/lodash.keys-3.1.2.tgz",
+              "version": "4.0.6",
+              "from": "lodash.keys@>=4.0.0 <5.0.0",
+              "resolved": "https://registry.npmjs.org/lodash.keys/-/lodash.keys-4.0.6.tgz"
+            },
+            "lodash.rest": {
+              "version": "4.0.2",
+              "from": "lodash.rest@>=4.0.0 <5.0.0",
+              "resolved": "https://registry.npmjs.org/lodash.rest/-/lodash.rest-4.0.2.tgz"
+            },
+            "lodash.templatesettings": {
+              "version": "4.0.1",
+              "from": "lodash.templatesettings@>=4.0.0 <5.0.0",
+              "resolved": "https://registry.npmjs.org/lodash.templatesettings/-/lodash.templatesettings-4.0.1.tgz",
               "dependencies": {
-                "lodash._getnative": {
-                  "version": "3.9.1",
-                  "from": "lodash._getnative@>=3.0.0 <4.0.0",
-                  "resolved": "https://registry.npmjs.org/lodash._getnative/-/lodash._getnative-3.9.1.tgz"
-                },
-                "lodash.isarguments": {
-                  "version": "3.0.8",
-                  "from": "lodash.isarguments@>=3.0.0 <4.0.0",
-                  "resolved": "https://registry.npmjs.org/lodash.isarguments/-/lodash.isarguments-3.0.8.tgz"
-                },
-                "lodash.isarray": {
-                  "version": "3.0.4",
-                  "from": "lodash.isarray@>=3.0.0 <4.0.0",
-                  "resolved": "https://registry.npmjs.org/lodash.isarray/-/lodash.isarray-3.0.4.tgz"
+                "lodash.escape": {
+                  "version": "4.0.0",
+                  "from": "lodash.escape@>=4.0.0 <5.0.0",
+                  "resolved": "https://registry.npmjs.org/lodash.escape/-/lodash.escape-4.0.0.tgz"
                 }
               }
             },
-            "lodash.restparam": {
-              "version": "3.6.1",
-              "from": "lodash.restparam@>=3.0.0 <4.0.0",
-              "resolved": "https://registry.npmjs.org/lodash.restparam/-/lodash.restparam-3.6.1.tgz"
-            },
-            "lodash.templatesettings": {
-              "version": "3.1.1",
-              "from": "lodash.templatesettings@>=3.0.0 <4.0.0",
-              "resolved": "https://registry.npmjs.org/lodash.templatesettings/-/lodash.templatesettings-3.1.1.tgz"
+            "lodash.tostring": {
+              "version": "4.1.2",
+              "from": "lodash.tostring@>=4.0.0 <5.0.0",
+              "resolved": "https://registry.npmjs.org/lodash.tostring/-/lodash.tostring-4.1.2.tgz"
             }
           }
         },
@@ -14150,40 +14189,6 @@
             }
           }
         },
-        "node-haste": {
-          "version": "2.9.6",
-          "from": "node-haste@>=2.5.0 <3.0.0",
-          "resolved": "https://registry.npmjs.org/node-haste/-/node-haste-2.9.6.tgz",
-          "dependencies": {
-            "absolute-path": {
-              "version": "0.0.0",
-              "from": "absolute-path@>=0.0.0 <0.0.1",
-              "resolved": "https://registry.npmjs.org/absolute-path/-/absolute-path-0.0.0.tgz"
-            },
-            "debug": {
-              "version": "2.2.0",
-              "from": "debug@>=2.2.0 <3.0.0",
-              "resolved": "https://registry.npmjs.org/debug/-/debug-2.2.0.tgz",
-              "dependencies": {
-                "ms": {
-                  "version": "0.7.1",
-                  "from": "ms@0.7.1",
-                  "resolved": "https://registry.npmjs.org/ms/-/ms-0.7.1.tgz"
-                }
-              }
-            },
-            "denodeify": {
-              "version": "1.2.1",
-              "from": "denodeify@>=1.2.1 <2.0.0",
-              "resolved": "https://registry.npmjs.org/denodeify/-/denodeify-1.2.1.tgz"
-            },
-            "throat": {
-              "version": "2.0.2",
-              "from": "throat@>=2.0.2 <3.0.0",
-              "resolved": "https://registry.npmjs.org/throat/-/throat-2.0.2.tgz"
-            }
-          }
-        },
         "optimist": {
           "version": "0.6.1",
           "from": "optimist@>=0.6.1 <0.7.0",
@@ -14225,7 +14230,7 @@
             },
             "fb-watchman": {
               "version": "1.9.0",
-              "from": "fb-watchman@>=1.8.0 <2.0.0",
+              "from": "fb-watchman@>=1.9.0 <2.0.0",
               "resolved": "https://registry.npmjs.org/fb-watchman/-/fb-watchman-1.9.0.tgz",
               "dependencies": {
                 "bser": {
@@ -14291,9 +14296,9 @@
           }
         },
         "which": {
-          "version": "1.2.4",
+          "version": "1.2.8",
           "from": "which@>=1.1.1 <2.0.0",
-          "resolved": "https://registry.npmjs.org/which/-/which-1.2.4.tgz",
+          "resolved": "https://registry.npmjs.org/which/-/which-1.2.8.tgz",
           "dependencies": {
             "is-absolute": {
               "version": "0.1.7",
@@ -14353,9 +14358,9 @@
       }
     },
     "object-assign": {
-      "version": "4.0.1",
-      "from": "object-assign@>=4.0.1 <5.0.0",
-      "resolved": "https://registry.npmjs.org/object-assign/-/object-assign-4.0.1.tgz"
+      "version": "4.1.0",
+      "from": "object-assign@>=4.1.0 <5.0.0",
+      "resolved": "https://registry.npmjs.org/object-assign/-/object-assign-4.1.0.tgz"
     },
     "platform": {
       "version": "1.3.1",
diff --git a/package.json b/package.json
index 38b3480878..d42afd0864 100644
--- a/package.json
+++ b/package.json
@@ -1,7 +1,7 @@
 {
   "name": "react-build",
   "private": true,
-  "version": "15.0.2",
+  "version": "15.1.0-alpha.1",
   "devDependencies": {
     "async": "^1.5.0",
     "babel-cli": "^6.6.5",
@@ -48,9 +48,9 @@
     "gulp-babel": "^6.0.0",
     "gulp-flatten": "^0.2.0",
     "gzip-js": "~0.3.2",
-    "jest-cli": "^0.9.0",
+    "jest-cli": "^12.0.2",
     "loose-envify": "^1.1.0",
-    "object-assign": "^4.0.1",
+    "object-assign": "^4.1.0",
     "platform": "^1.1.0",
     "run-sequence": "^1.1.4",
     "through2": "^2.0.0",
diff --git a/packages/react-addons/package.json b/packages/react-addons/package.json
index b3234fe909..062f360a23 100644
--- a/packages/react-addons/package.json
+++ b/packages/react-addons/package.json
@@ -1,6 +1,6 @@
 {
   "name": "react-addons-template",
-  "version": "15.0.2",
+  "version": "15.1.0-alpha.1",
   "main": "index.js",
   "repository": "facebook/react",
   "keywords": [
@@ -10,6 +10,6 @@
   "license": "BSD-3-Clause",
   "dependencies": {},
   "peerDependencies": {
-    "react": "^15.0.2"
+    "react": "^15.1.0-alpha.1"
   }
 }
diff --git a/packages/react-dom/package.json b/packages/react-dom/package.json
index dca80f0d0a..648d45765d 100644
--- a/packages/react-dom/package.json
+++ b/packages/react-dom/package.json
@@ -1,6 +1,6 @@
 {
   "name": "react-dom",
-  "version": "15.0.2",
+  "version": "15.1.0-alpha.1",
   "description": "React package for working with the DOM.",
   "main": "index.js",
   "repository": "facebook/react",
@@ -14,6 +14,6 @@
   "homepage": "https://facebook.github.io/react/",
   "dependencies": {},
   "peerDependencies": {
-    "react": "^15.0.2"
+    "react": "^15.1.0-alpha.1"
   }
 }
diff --git a/packages/react-native-renderer/package.json b/packages/react-native-renderer/package.json
index 89adaee983..30b424a62c 100644
--- a/packages/react-native-renderer/package.json
+++ b/packages/react-native-renderer/package.json
@@ -1,6 +1,6 @@
 {
   "name": "react-native-renderer",
-  "version": "15.0.2",
+  "version": "15.1.0-alpha.1",
   "description": "React package for use inside react-native.",
   "main": "index.js",
   "repository": "facebook/react",
@@ -14,6 +14,6 @@
   },
   "homepage": "https://facebook.github.io/react-native/",
   "dependencies": {
-    "react": "^15.0.2"
+    "react": "^15.1.0-alpha.1"
   }
 }
diff --git a/packages/react/package.json b/packages/react/package.json
index 4a3ef56b14..ca9ab105aa 100644
--- a/packages/react/package.json
+++ b/packages/react/package.json
@@ -1,7 +1,7 @@
 {
   "name": "react",
   "description": "React is a JavaScript library for building user interfaces.",
-  "version": "15.0.2",
+  "version": "15.1.0-alpha.1",
   "keywords": [
     "react"
   ],
@@ -25,7 +25,7 @@
   "dependencies": {
     "fbjs": "^0.8.0",
     "loose-envify": "^1.1.0",
-    "object-assign": "^4.0.1"
+    "object-assign": "^4.1.0"
   },
   "browserify": {
     "transform": [
diff --git a/src/ReactVersion.js b/src/ReactVersion.js
index 5735f2b6c6..f30ca3df87 100644
--- a/src/ReactVersion.js
+++ b/src/ReactVersion.js
@@ -11,4 +11,4 @@
 
 'use strict';
 
-module.exports = '15.0.2';
+module.exports = '15.1.0-alpha.1';
diff --git a/src/addons/ReactComponentWithPureRenderMixin.js b/src/addons/ReactComponentWithPureRenderMixin.js
index afafbdaa76..cf00d7cb3d 100644
--- a/src/addons/ReactComponentWithPureRenderMixin.js
+++ b/src/addons/ReactComponentWithPureRenderMixin.js
@@ -36,6 +36,8 @@ var shallowCompare = require('shallowCompare');
  * complex data structures this mixin may have false-negatives for deeper
  * differences. Only mixin to components which have simple props and state, or
  * use `forceUpdate()` when you know deep data structures have changed.
+ *
+ * See https://facebook.github.io/react/docs/pure-render-mixin.html
  */
 var ReactComponentWithPureRenderMixin = {
   shouldComponentUpdate: function(nextProps, nextState) {
diff --git a/src/addons/ReactFragment.js b/src/addons/ReactFragment.js
index f16ccf8bc0..5d83e84533 100644
--- a/src/addons/ReactFragment.js
+++ b/src/addons/ReactFragment.js
@@ -31,8 +31,11 @@ var numericPropertyRegex = /^\d+$/;
 var warnedAboutNumeric = false;
 
 var ReactFragment = {
-  // Wrap a keyed object in an opaque proxy that warns you if you access any
-  // of its properties.
+  /**
+   * Wrap a keyed object in an opaque proxy that warns you if you access any
+   * of its properties.
+   * See https://facebook.github.io/react/docs/create-fragment.html
+   */
   create: function(object) {
     if (typeof object !== 'object' || !object || Array.isArray(object)) {
       warning(
diff --git a/src/addons/ReactWithAddons.js b/src/addons/ReactWithAddons.js
index bd13ea495f..94102c5c2e 100644
--- a/src/addons/ReactWithAddons.js
+++ b/src/addons/ReactWithAddons.js
@@ -34,7 +34,7 @@ React.addons = {
 };
 
 if (__DEV__) {
-  React.addons.Perf = require('ReactDefaultPerf');
+  React.addons.Perf = require('ReactPerf');
   React.addons.TestUtils = require('ReactTestUtils');
 }
 
diff --git a/src/addons/link/LinkedStateMixin.js b/src/addons/link/LinkedStateMixin.js
index c45a79faad..3e2ca17604 100644
--- a/src/addons/link/LinkedStateMixin.js
+++ b/src/addons/link/LinkedStateMixin.js
@@ -16,6 +16,7 @@ var ReactStateSetters = require('ReactStateSetters');
 
 /**
  * A simple mixin around ReactLink.forState().
+ * See https://facebook.github.io/react/docs/two-way-binding-helpers.html
  */
 var LinkedStateMixin = {
   /**
diff --git a/src/addons/link/ReactLink.js b/src/addons/link/ReactLink.js
index ea6435c92b..d327b4f8ec 100644
--- a/src/addons/link/ReactLink.js
+++ b/src/addons/link/ReactLink.js
@@ -37,6 +37,9 @@
 var React = require('React');
 
 /**
+ * Deprecated: An an easy way to express two-way binding with React. 
+ * See https://facebook.github.io/react/docs/two-way-binding-helpers.html
+ *
  * @param {*} value current value of the link
  * @param {function} requestChange callback to request a change
  */
diff --git a/src/addons/shallowCompare.js b/src/addons/shallowCompare.js
index 33e4591ba8..a6b7a1095d 100644
--- a/src/addons/shallowCompare.js
+++ b/src/addons/shallowCompare.js
@@ -16,6 +16,7 @@ var shallowEqual = require('shallowEqual');
 /**
  * Does a shallow comparison for props and state.
  * See ReactComponentWithPureRenderMixin
+ * See also https://facebook.github.io/react/docs/shallow-compare.html
  */
 function shallowCompare(instance, nextProps, nextState) {
   return (
diff --git a/src/addons/transitions/ReactCSSTransitionGroup.js b/src/addons/transitions/ReactCSSTransitionGroup.js
index 4177ec790b..6d61c2884a 100644
--- a/src/addons/transitions/ReactCSSTransitionGroup.js
+++ b/src/addons/transitions/ReactCSSTransitionGroup.js
@@ -41,6 +41,11 @@ function createTransitionTimeoutPropValidator(transitionType) {
   };
 }
 
+/**
+ * An easy way to perform CSS transitions and animations when a React component
+ * enters or leaves the DOM.
+ * See https://facebook.github.io/react/docs/animation.html#high-level-api-reactcsstransitiongroup
+ */
 var ReactCSSTransitionGroup = React.createClass({
   displayName: 'ReactCSSTransitionGroup',
 
diff --git a/src/addons/transitions/ReactTransitionGroup.js b/src/addons/transitions/ReactTransitionGroup.js
index 6d6df1a80b..a2c935eeb2 100644
--- a/src/addons/transitions/ReactTransitionGroup.js
+++ b/src/addons/transitions/ReactTransitionGroup.js
@@ -16,6 +16,11 @@ var ReactTransitionChildMapping = require('ReactTransitionChildMapping');
 
 var emptyFunction = require('emptyFunction');
 
+/**
+ * A basis for animatins. When children are declaratively added or removed,
+ * special lifecycle hooks are called.
+ * See https://facebook.github.io/react/docs/animation.html#low-level-api-reacttransitiongroup
+ */
 var ReactTransitionGroup = React.createClass({
   displayName: 'ReactTransitionGroup',
 
diff --git a/src/addons/update.js b/src/addons/update.js
index cc2434e2bd..8704993c11 100644
--- a/src/addons/update.js
+++ b/src/addons/update.js
@@ -66,6 +66,10 @@ function invariantArrayCase(value, spec, command) {
   );
 }
 
+/**
+ * Returns a updated shallow copy of an object without mutating the original.
+ * See https://facebook.github.io/react/docs/update.html for details.
+ */
 function update(value, spec) {
   invariant(
     typeof spec === 'object',
diff --git a/src/core/__tests__/ReactErrorBoundaries-test.js b/src/core/__tests__/ReactErrorBoundaries-test.js
index 0ba37323d5..c61d1f524d 100644
--- a/src/core/__tests__/ReactErrorBoundaries-test.js
+++ b/src/core/__tests__/ReactErrorBoundaries-test.js
@@ -13,11 +13,13 @@
 
 var React;
 var ReactDOM;
+var ReactDOMServer;
 
 describe('ReactErrorBoundaries', function() {
 
   beforeEach(function() {
     ReactDOM = require('ReactDOM');
+    ReactDOMServer = require('ReactDOMServer');
     React = require('React');
   });
 
@@ -50,11 +52,46 @@ describe('ReactErrorBoundaries', function() {
 
     var EventPluginHub = require('EventPluginHub');
     var container = document.createElement('div');
-    EventPluginHub.putListener = jest.genMockFn();
+    EventPluginHub.putListener = jest.fn();
     ReactDOM.render(<Boundary />, container);
     expect(EventPluginHub.putListener).not.toBeCalled();
   });
 
+  it('renders an error state (ssr)', function() {
+    class Angry extends React.Component {
+      render() {
+        throw new Error('Please, do not render me.');
+      }
+    }
+
+    class Boundary extends React.Component {
+      constructor(props) {
+        super(props);
+        this.state = {error: false};
+      }
+      render() {
+        if (!this.state.error) {
+          return (<div><button onClick={this.onClick}>ClickMe</button><Angry /></div>);
+        } else {
+          return (<div>Happy Birthday!</div>);
+        }
+      }
+      onClick() {
+        /* do nothing */
+      }
+      unstable_handleError() {
+        this.setState({error: true});
+      }
+    }
+
+    var EventPluginHub = require('EventPluginHub');
+    var container = document.createElement('div');
+    EventPluginHub.putListener = jest.fn();
+    container.innerHTML = ReactDOMServer.renderToString(<Boundary />);
+    expect(container.firstChild.innerHTML).toBe('Happy Birthday!');
+    expect(EventPluginHub.putListener).not.toBeCalled();
+  });
+
   it('will catch exceptions in componentWillUnmount', function() {
     class ErrorBoundary extends React.Component {
       constructor() {
@@ -120,7 +157,7 @@ describe('ReactErrorBoundaries', function() {
 
     var EventPluginHub = require('EventPluginHub');
     var container = document.createElement('div');
-    EventPluginHub.putListener = jest.genMockFn();
+    EventPluginHub.putListener = jest.fn();
     ReactDOM.render(<Boundary />, container);
     expect(EventPluginHub.putListener).toBeCalled();
   });
diff --git a/src/isomorphic/ReactDebugInstanceMap.js b/src/isomorphic/ReactDebugInstanceMap.js
deleted file mode 100644
index 50dddf4ad0..0000000000
--- a/src/isomorphic/ReactDebugInstanceMap.js
+++ /dev/null
@@ -1,124 +0,0 @@
-/**
- * Copyright 2016-present, Facebook, Inc.
- * All rights reserved.
- *
- * This source code is licensed under the BSD-style license found in the
- * LICENSE file in the root directory of this source tree. An additional grant
- * of patent rights can be found in the PATENTS file in the same directory.
- *
- * @providesModule ReactDebugInstanceMap
- */
-
-'use strict';
-
-var warning = require('warning');
-
-function checkValidInstance(internalInstance) {
-  if (!internalInstance) {
-    warning(
-      false,
-      'There is an internal error in the React developer tools integration. ' +
-      'Instead of an internal instance, received %s. ' +
-      'Please report this as a bug in React.',
-      internalInstance
-    );
-    return false;
-  }
-  var isValid = typeof internalInstance.mountComponent === 'function';
-  warning(
-    isValid,
-    'There is an internal error in the React developer tools integration. ' +
-    'Instead of an internal instance, received an object with the following ' +
-    'keys: %s. Please report this as a bug in React.',
-    Object.keys(internalInstance).join(', ')
-  );
-  return isValid;
-}
-
-var idCounter = 1;
-var instancesByIDs = {};
-var instancesToIDs;
-
-function getIDForInstance(internalInstance) {
-  if (!instancesToIDs) {
-    instancesToIDs = new WeakMap();
-  }
-  if (instancesToIDs.has(internalInstance)) {
-    return instancesToIDs.get(internalInstance);
-  } else {
-    var instanceID = (idCounter++).toString();
-    instancesToIDs.set(internalInstance, instanceID);
-    return instanceID;
-  }
-}
-
-function getInstanceByID(instanceID) {
-  return instancesByIDs[instanceID] || null;
-}
-
-function isRegisteredInstance(internalInstance) {
-  var instanceID = getIDForInstance(internalInstance);
-  if (instanceID) {
-    return instancesByIDs.hasOwnProperty(instanceID);
-  } else {
-    return false;
-  }
-}
-
-function registerInstance(internalInstance) {
-  var instanceID = getIDForInstance(internalInstance);
-  if (instanceID) {
-    instancesByIDs[instanceID] = internalInstance;
-  }
-}
-
-function unregisterInstance(internalInstance) {
-  var instanceID = getIDForInstance(internalInstance);
-  if (instanceID) {
-    delete instancesByIDs[instanceID];
-  }
-}
-
-var ReactDebugInstanceMap = {
-  getIDForInstance(internalInstance) {
-    if (!checkValidInstance(internalInstance)) {
-      return null;
-    }
-    return getIDForInstance(internalInstance);
-  },
-  getInstanceByID(instanceID) {
-    return getInstanceByID(instanceID);
-  },
-  isRegisteredInstance(internalInstance) {
-    if (!checkValidInstance(internalInstance)) {
-      return false;
-    }
-    return isRegisteredInstance(internalInstance);
-  },
-  registerInstance(internalInstance) {
-    if (!checkValidInstance(internalInstance)) {
-      return;
-    }
-    warning(
-      !isRegisteredInstance(internalInstance),
-      'There is an internal error in the React developer tools integration. ' +
-      'A registered instance should not be registered again. ' +
-      'Please report this as a bug in React.'
-    );
-    registerInstance(internalInstance);
-  },
-  unregisterInstance(internalInstance) {
-    if (!checkValidInstance(internalInstance)) {
-      return;
-    }
-    warning(
-      isRegisteredInstance(internalInstance),
-      'There is an internal error in the React developer tools integration. ' +
-      'An unregistered instance should not be unregistered again. ' +
-      'Please report this as a bug in React.'
-    );
-    unregisterInstance(internalInstance);
-  },
-};
-
-module.exports = ReactDebugInstanceMap;
diff --git a/src/isomorphic/ReactDebugTool.js b/src/isomorphic/ReactDebugTool.js
index 4d2c2a3536..9c084ad52f 100644
--- a/src/isomorphic/ReactDebugTool.js
+++ b/src/isomorphic/ReactDebugTool.js
@@ -11,7 +11,9 @@
 
 'use strict';
 
-var ReactInvalidSetStateWarningDevTool = require('ReactInvalidSetStateWarningDevTool');
+var ExecutionEnvironment = require('ExecutionEnvironment');
+
+var performanceNow = require('performanceNow');
 var warning = require('warning');
 
 var eventHandlers = [];
@@ -37,6 +39,70 @@ function emitEvent(handlerFunctionName, arg1, arg2, arg3, arg4, arg5) {
   }
 }
 
+var isProfiling = false;
+var flushHistory = [];
+var currentFlushNesting = 0;
+var currentFlushMeasurements = null;
+var currentFlushStartTime = null;
+var currentTimerDebugID = null;
+var currentTimerStartTime = null;
+var currentTimerType = null;
+
+function clearHistory() {
+  ReactComponentTreeDevtool.purgeUnmountedComponents();
+  ReactNativeOperationHistoryDevtool.clearHistory();
+}
+
+function getTreeSnapshot(registeredIDs) {
+  return registeredIDs.reduce((tree, id) => {
+    var ownerID = ReactComponentTreeDevtool.getOwnerID(id);
+    var parentID = ReactComponentTreeDevtool.getParentID(id);
+    tree[id] = {
+      displayName: ReactComponentTreeDevtool.getDisplayName(id),
+      text: ReactComponentTreeDevtool.getText(id),
+      updateCount: ReactComponentTreeDevtool.getUpdateCount(id),
+      childIDs: ReactComponentTreeDevtool.getChildIDs(id),
+      // Text nodes don't have owners but this is close enough.
+      ownerID: ownerID || ReactComponentTreeDevtool.getOwnerID(parentID),
+      parentID,
+    };
+    return tree;
+  }, {});
+}
+
+function resetMeasurements() {
+  if (__DEV__) {
+    var previousStartTime = currentFlushStartTime;
+    var previousMeasurements = currentFlushMeasurements || [];
+    var previousOperations = ReactNativeOperationHistoryDevtool.getHistory();
+
+    if (!isProfiling || currentFlushNesting === 0) {
+      currentFlushStartTime = null;
+      currentFlushMeasurements = null;
+      clearHistory();
+      return;
+    }
+
+    if (previousMeasurements.length || previousOperations.length) {
+      var registeredIDs = ReactComponentTreeDevtool.getRegisteredIDs();
+      flushHistory.push({
+        duration: performanceNow() - previousStartTime,
+        measurements: previousMeasurements || [],
+        operations: previousOperations || [],
+        treeSnapshot: getTreeSnapshot(registeredIDs),
+      });
+    }
+
+    clearHistory();
+    currentFlushStartTime = performanceNow();
+    currentFlushMeasurements = [];
+  }
+}
+
+function checkDebugID(debugID) {
+  warning(debugID, 'ReactDebugTool: debugID may not be empty.');
+}
+
 var ReactDebugTool = {
   addDevtool(devtool) {
     eventHandlers.push(devtool);
@@ -49,29 +115,157 @@ var ReactDebugTool = {
       }
     }
   },
+  beginProfiling() {
+    if (__DEV__) {
+      if (isProfiling) {
+        return;
+      }
+
+      isProfiling = true;
+      flushHistory.length = 0;
+      resetMeasurements();
+    }
+  },
+  endProfiling() {
+    if (__DEV__) {
+      if (!isProfiling) {
+        return;
+      }
+
+      isProfiling = false;
+      resetMeasurements();
+    }
+  },
+  getFlushHistory() {
+    if (__DEV__) {
+      return flushHistory;
+    }
+  },
+  onBeginFlush() {
+    if (__DEV__) {
+      currentFlushNesting++;
+      resetMeasurements();
+    }
+    emitEvent('onBeginFlush');
+  },
+  onEndFlush() {
+    if (__DEV__) {
+      resetMeasurements();
+      currentFlushNesting--;
+    }
+    emitEvent('onEndFlush');
+  },
+  onBeginLifeCycleTimer(debugID, timerType) {
+    checkDebugID(debugID);
+    emitEvent('onBeginLifeCycleTimer', debugID, timerType);
+    if (__DEV__) {
+      if (isProfiling && currentFlushNesting > 0) {
+        warning(
+          !currentTimerType,
+          'There is an internal error in the React performance measurement code. ' +
+          'Did not expect %s timer to start while %s timer is still in ' +
+          'progress for %s instance.',
+          timerType,
+          currentTimerType || 'no',
+          (debugID === currentTimerDebugID) ? 'the same' : 'another'
+        );
+        currentTimerStartTime = performanceNow();
+        currentTimerDebugID = debugID;
+        currentTimerType = timerType;
+      }
+    }
+  },
+  onEndLifeCycleTimer(debugID, timerType) {
+    checkDebugID(debugID);
+    if (__DEV__) {
+      if (isProfiling && currentFlushNesting > 0) {
+        warning(
+          currentTimerType === timerType,
+          'There is an internal error in the React performance measurement code. ' +
+          'We did not expect %s timer to stop while %s timer is still in ' +
+          'progress for %s instance. Please report this as a bug in React.',
+          timerType,
+          currentTimerType || 'no',
+          (debugID === currentTimerDebugID) ? 'the same' : 'another'
+        );
+        currentFlushMeasurements.push({
+          timerType,
+          instanceID: debugID,
+          duration: performanceNow() - currentTimerStartTime,
+        });
+        currentTimerStartTime = null;
+        currentTimerDebugID = null;
+        currentTimerType = null;
+      }
+    }
+    emitEvent('onEndLifeCycleTimer', debugID, timerType);
+  },
+  onBeginReconcilerTimer(debugID, timerType) {
+    checkDebugID(debugID);
+    emitEvent('onBeginReconcilerTimer', debugID, timerType);
+  },
+  onEndReconcilerTimer(debugID, timerType) {
+    checkDebugID(debugID);
+    emitEvent('onEndReconcilerTimer', debugID, timerType);
+  },
   onBeginProcessingChildContext() {
     emitEvent('onBeginProcessingChildContext');
   },
   onEndProcessingChildContext() {
     emitEvent('onEndProcessingChildContext');
   },
+  onNativeOperation(debugID, type, payload) {
+    checkDebugID(debugID);
+    emitEvent('onNativeOperation', debugID, type, payload);
+  },
   onSetState() {
     emitEvent('onSetState');
   },
-  onMountRootComponent(internalInstance) {
-    emitEvent('onMountRootComponent', internalInstance);
+  onSetDisplayName(debugID, displayName) {
+    checkDebugID(debugID);
+    emitEvent('onSetDisplayName', debugID, displayName);
   },
-  onMountComponent(internalInstance) {
-    emitEvent('onMountComponent', internalInstance);
+  onSetChildren(debugID, childDebugIDs) {
+    checkDebugID(debugID);
+    emitEvent('onSetChildren', debugID, childDebugIDs);
   },
-  onUpdateComponent(internalInstance) {
-    emitEvent('onUpdateComponent', internalInstance);
+  onSetOwner(debugID, ownerDebugID) {
+    checkDebugID(debugID);
+    emitEvent('onSetOwner', debugID, ownerDebugID);
   },
-  onUnmountComponent(internalInstance) {
-    emitEvent('onUnmountComponent', internalInstance);
+  onSetText(debugID, text) {
+    checkDebugID(debugID);
+    emitEvent('onSetText', debugID, text);
+  },
+  onMountRootComponent(debugID) {
+    checkDebugID(debugID);
+    emitEvent('onMountRootComponent', debugID);
+  },
+  onMountComponent(debugID) {
+    checkDebugID(debugID);
+    emitEvent('onMountComponent', debugID);
+  },
+  onUpdateComponent(debugID) {
+    checkDebugID(debugID);
+    emitEvent('onUpdateComponent', debugID);
+  },
+  onUnmountComponent(debugID) {
+    checkDebugID(debugID);
+    emitEvent('onUnmountComponent', debugID);
   },
 };
 
-ReactDebugTool.addDevtool(ReactInvalidSetStateWarningDevTool);
+if (__DEV__) {
+  var ReactInvalidSetStateWarningDevTool = require('ReactInvalidSetStateWarningDevTool');
+  var ReactNativeOperationHistoryDevtool = require('ReactNativeOperationHistoryDevtool');
+  var ReactComponentTreeDevtool = require('ReactComponentTreeDevtool');
+  ReactDebugTool.addDevtool(ReactInvalidSetStateWarningDevTool);
+  ReactDebugTool.addDevtool(ReactComponentTreeDevtool);
+  ReactDebugTool.addDevtool(ReactNativeOperationHistoryDevtool);
+  var url = (ExecutionEnvironment.canUseDOM && window.location.href) || '';
+  if ((/[?&]react_perf\b/).test(url)) {
+    ReactDebugTool.beginProfiling();
+  }
+}
 
 module.exports = ReactDebugTool;
diff --git a/src/isomorphic/ReactPerf.js b/src/isomorphic/ReactPerf.js
new file mode 100644
index 0000000000..4c631a7f13
--- /dev/null
+++ b/src/isomorphic/ReactPerf.js
@@ -0,0 +1,371 @@
+/**
+ * Copyright 2016-present, Facebook, Inc.
+ * All rights reserved.
+ *
+ * This source code is licensed under the BSD-style license found in the
+ * LICENSE file in the root directory of this source tree. An additional grant
+ * of patent rights can be found in the PATENTS file in the same directory.
+ *
+ * @providesModule ReactPerf
+ */
+
+'use strict';
+
+var ReactDebugTool = require('ReactDebugTool');
+var warning = require('warning');
+
+function roundFloat(val, base = 2) {
+  var n = Math.pow(10, base);
+  return Math.floor(val * n) / n;
+}
+
+function getFlushHistory() {
+  return ReactDebugTool.getFlushHistory();
+}
+
+function getExclusive(flushHistory = getFlushHistory()) {
+  var aggregatedStats = {};
+  var affectedIDs = {};
+
+  function updateAggregatedStats(treeSnapshot, instanceID, timerType, applyUpdate) {
+    var {displayName} = treeSnapshot[instanceID];
+    var key = displayName;
+    var stats = aggregatedStats[key];
+    if (!stats) {
+      affectedIDs[key] = {};
+      stats = aggregatedStats[key] = {
+        key,
+        instanceCount: 0,
+        counts: {},
+        durations: {},
+        totalDuration: 0,
+      };
+    }
+    if (!stats.durations[timerType]) {
+      stats.durations[timerType] = 0;
+    }
+    if (!stats.counts[timerType]) {
+      stats.counts[timerType] = 0;
+    }
+    affectedIDs[key][instanceID] = true;
+    applyUpdate(stats);
+  }
+
+  flushHistory.forEach(flush => {
+    var {measurements, treeSnapshot} = flush;
+    measurements.forEach(measurement => {
+      var {duration, instanceID, timerType} = measurement;
+      updateAggregatedStats(treeSnapshot, instanceID, timerType, stats => {
+        stats.totalDuration += duration;
+        stats.durations[timerType] += duration;
+        stats.counts[timerType]++;
+      });
+    });
+  });
+
+  return Object.keys(aggregatedStats)
+    .map(key => ({
+      ...aggregatedStats[key],
+      instanceCount: Object.keys(affectedIDs[key]).length,
+    }))
+    .sort((a, b) =>
+      b.totalDuration - a.totalDuration
+    );
+}
+
+function getInclusive(flushHistory = getFlushHistory()) {
+  var aggregatedStats = {};
+  var affectedIDs = {};
+
+  function updateAggregatedStats(treeSnapshot, instanceID, applyUpdate) {
+    var {displayName, ownerID} = treeSnapshot[instanceID];
+    var owner = treeSnapshot[ownerID];
+    var key = (owner ? owner.displayName + ' > ' : '') + displayName;
+    var stats = aggregatedStats[key];
+    if (!stats) {
+      affectedIDs[key] = {};
+      stats = aggregatedStats[key] = {
+        key,
+        instanceCount: 0,
+        inclusiveRenderDuration: 0,
+        renderCount: 0,
+      };
+    }
+    affectedIDs[key][instanceID] = true;
+    applyUpdate(stats);
+  }
+
+  var isCompositeByID = {};
+  flushHistory.forEach(flush => {
+    var {measurements} = flush;
+    measurements.forEach(measurement => {
+      var {instanceID, timerType} = measurement;
+      if (timerType !== 'render') {
+        return;
+      }
+      isCompositeByID[instanceID] = true;
+    });
+  });
+
+  flushHistory.forEach(flush => {
+    var {measurements, treeSnapshot} = flush;
+    measurements.forEach(measurement => {
+      var {duration, instanceID, timerType} = measurement;
+      if (timerType !== 'render') {
+        return;
+      }
+      updateAggregatedStats(treeSnapshot, instanceID, stats => {
+        stats.renderCount++;
+      });
+      var nextParentID = instanceID;
+      while (nextParentID) {
+        // As we traverse parents, only count inclusive time towards composites.
+        // We know something is a composite if its render() was called.
+        if (isCompositeByID[nextParentID]) {
+          updateAggregatedStats(treeSnapshot, nextParentID, stats => {
+            stats.inclusiveRenderDuration += duration;
+          });
+        }
+        nextParentID = treeSnapshot[nextParentID].parentID;
+      }
+    });
+  });
+
+  return Object.keys(aggregatedStats)
+    .map(key => ({
+      ...aggregatedStats[key],
+      instanceCount: Object.keys(affectedIDs[key]).length,
+    }))
+    .sort((a, b) =>
+      b.inclusiveRenderDuration - a.inclusiveRenderDuration
+    );
+}
+
+function getWasted(flushHistory = getFlushHistory()) {
+  var aggregatedStats = {};
+  var affectedIDs = {};
+
+  function updateAggregatedStats(treeSnapshot, instanceID, applyUpdate) {
+    var {displayName, ownerID} = treeSnapshot[instanceID];
+    var owner = treeSnapshot[ownerID];
+    var key = (owner ? owner.displayName + ' > ' : '') + displayName;
+    var stats = aggregatedStats[key];
+    if (!stats) {
+      affectedIDs[key] = {};
+      stats = aggregatedStats[key] = {
+        key,
+        instanceCount: 0,
+        inclusiveRenderDuration: 0,
+        renderCount: 0,
+      };
+    }
+    affectedIDs[key][instanceID] = true;
+    applyUpdate(stats);
+  }
+
+  flushHistory.forEach(flush => {
+    var {measurements, treeSnapshot, operations} = flush;
+    var isDefinitelyNotWastedByID = {};
+
+    // Find native components associated with an operation in this batch.
+    // Mark all components in their parent tree as definitely not wasted.
+    operations.forEach(operation => {
+      var {instanceID} = operation;
+      var nextParentID = instanceID;
+      while (nextParentID) {
+        isDefinitelyNotWastedByID[nextParentID] = true;
+        nextParentID = treeSnapshot[nextParentID].parentID;
+      }
+    });
+
+    // Find composite components that rendered in this batch.
+    // These are potential candidates for being wasted renders.
+    var renderedCompositeIDs = {};
+    measurements.forEach(measurement => {
+      var {instanceID, timerType} = measurement;
+      if (timerType !== 'render') {
+        return;
+      }
+      renderedCompositeIDs[instanceID] = true;
+    });
+
+    measurements.forEach(measurement => {
+      var {duration, instanceID, timerType} = measurement;
+      if (timerType !== 'render') {
+        return;
+      }
+
+      // If there was a DOM update below this component, or it has just been
+      // mounted, its render() is not considered wasted.
+      var { updateCount } = treeSnapshot[instanceID];
+      if (isDefinitelyNotWastedByID[instanceID] || updateCount === 0) {
+        return;
+      }
+
+      // We consider this render() wasted.
+      updateAggregatedStats(treeSnapshot, instanceID, stats => {
+        stats.renderCount++;
+      });
+
+      var nextParentID = instanceID;
+      while (nextParentID) {
+        // Any parents rendered during this batch are considered wasted
+        // unless we previously marked them as dirty.
+        var isWasted =
+          renderedCompositeIDs[nextParentID] &&
+          !isDefinitelyNotWastedByID[nextParentID];
+        if (isWasted) {
+          updateAggregatedStats(treeSnapshot, nextParentID, stats => {
+            stats.inclusiveRenderDuration += duration;
+          });
+        }
+        nextParentID = treeSnapshot[nextParentID].parentID;
+      }
+    });
+  });
+
+  return Object.keys(aggregatedStats)
+    .map(key => ({
+      ...aggregatedStats[key],
+      instanceCount: Object.keys(affectedIDs[key]).length,
+    }))
+    .sort((a, b) =>
+      b.inclusiveRenderDuration - a.inclusiveRenderDuration
+    );
+}
+
+function getOperations(flushHistory = getFlushHistory()) {
+  var stats = [];
+  flushHistory.forEach((flush, flushIndex) => {
+    var {operations, treeSnapshot} = flush;
+    operations.forEach(operation => {
+      var {instanceID, type, payload} = operation;
+      var {displayName, ownerID} = treeSnapshot[instanceID];
+      var owner = treeSnapshot[ownerID];
+      var key = (owner ? owner.displayName + ' > ' : '') + displayName;
+
+      stats.push({
+        flushIndex,
+        instanceID,
+        key,
+        type,
+        ownerID,
+        payload,
+      });
+    });
+  });
+  return stats;
+}
+
+function printExclusive(flushHistory) {
+  var stats = getExclusive(flushHistory);
+  var table = stats.map(item => {
+    var {key, instanceCount, totalDuration} = item;
+    var renderCount = item.counts.render || 0;
+    var renderDuration = item.durations.render || 0;
+    return {
+      'Component': key,
+      'Total time (ms)': roundFloat(totalDuration),
+      'Instance count': instanceCount,
+      'Total render time (ms)': roundFloat(renderDuration),
+      'Average render time (ms)': renderCount ?
+        roundFloat(renderDuration / renderCount) :
+        undefined,
+      'Render count': renderCount,
+      'Total lifecycle time (ms)': roundFloat(totalDuration - renderDuration),
+    };
+  });
+  console.table(table);
+}
+
+function printInclusive(flushHistory) {
+  var stats = getInclusive(flushHistory);
+  var table = stats.map(item => {
+    var {key, instanceCount, inclusiveRenderDuration, renderCount} = item;
+    return {
+      'Owner > Component': key,
+      'Inclusive render time (ms)': roundFloat(inclusiveRenderDuration),
+      'Instance count': instanceCount,
+      'Render count': renderCount,
+    };
+  });
+  console.table(table);
+}
+
+function printWasted(flushHistory) {
+  var stats = getWasted(flushHistory);
+  var table = stats.map(item => {
+    var {key, instanceCount, inclusiveRenderDuration, renderCount} = item;
+    return {
+      'Owner > Component': key,
+      'Inclusive wasted time (ms)': roundFloat(inclusiveRenderDuration),
+      'Instance count': instanceCount,
+      'Render count': renderCount,
+    };
+  });
+  console.table(table);
+}
+
+function printOperations(flushHistory) {
+  var stats = getOperations(flushHistory);
+  var table = stats.map(stat => ({
+    'Owner > Node': stat.key,
+    'Operation': stat.type,
+    'Payload': typeof stat.payload === 'object' ?
+      JSON.stringify(stat.payload) :
+      stat.payload,
+    'Flush index': stat.flushIndex,
+    'Owner Component ID': stat.ownerID,
+    'DOM Component ID': stat.instanceID,
+  }));
+  console.table(table);
+}
+
+var warnedAboutPrintDOM = false;
+function printDOM(measurements) {
+  warning(
+    warnedAboutPrintDOM,
+    '`ReactPerf.printDOM(...)` is deprecated. Use ' +
+    '`ReactPerf.printOperations(...)` instead.'
+  );
+  warnedAboutPrintDOM = true;
+  return printOperations(measurements);
+}
+
+var warnedAboutGetMeasurementsSummaryMap = false;
+function getMeasurementsSummaryMap(measurements) {
+  warning(
+    warnedAboutGetMeasurementsSummaryMap,
+    '`ReactPerf.getMeasurementsSummaryMap(...)` is deprecated. Use ' +
+    '`ReactPerf.getWasted(...)` instead.'
+  );
+  warnedAboutGetMeasurementsSummaryMap = true;
+  return getWasted(measurements);
+}
+
+function start() {
+  ReactDebugTool.beginProfiling();
+}
+
+function stop() {
+  ReactDebugTool.endProfiling();
+}
+
+var ReactPerfAnalysis = {
+  getLastMeasurements: getFlushHistory,
+  getExclusive,
+  getInclusive,
+  getWasted,
+  getOperations,
+  printExclusive,
+  printInclusive,
+  printWasted,
+  printOperations,
+  start,
+  stop,
+  // Deprecated:
+  printDOM,
+  getMeasurementsSummaryMap,
+};
+
+module.exports = ReactPerfAnalysis;
diff --git a/src/isomorphic/__tests__/ReactDebugInstanceMap-test.js b/src/isomorphic/__tests__/ReactDebugInstanceMap-test.js
deleted file mode 100644
index d9a063e2c6..0000000000
--- a/src/isomorphic/__tests__/ReactDebugInstanceMap-test.js
+++ /dev/null
@@ -1,173 +0,0 @@
-/**
- * Copyright 2016-present, Facebook, Inc.
- * All rights reserved.
- *
- * This source code is licensed under the BSD-style license found in the
- * LICENSE file in the root directory of this source tree. An additional grant
- * of patent rights can be found in the PATENTS file in the same directory.
- *
- * @emails react-core
- */
-
-'use strict';
-
-describe('ReactDebugInstanceMap', function() {
-  var React;
-  var ReactDebugInstanceMap;
-  var ReactDOM;
-
-  beforeEach(function() {
-    jest.resetModuleRegistry();
-    React = require('React');
-    ReactDebugInstanceMap = require('ReactDebugInstanceMap');
-    ReactDOM = require('ReactDOM');
-  });
-
-  function createStubInstance() {
-    return { mountComponent: () => {} };
-  }
-
-  it('should register and unregister instances', function() {
-    var inst1 = createStubInstance();
-    var inst2 = createStubInstance();
-
-    expect(ReactDebugInstanceMap.isRegisteredInstance(inst1)).toBe(false);
-    expect(ReactDebugInstanceMap.isRegisteredInstance(inst2)).toBe(false);
-
-    ReactDebugInstanceMap.registerInstance(inst1);
-    expect(ReactDebugInstanceMap.isRegisteredInstance(inst1)).toBe(true);
-    expect(ReactDebugInstanceMap.isRegisteredInstance(inst2)).toBe(false);
-
-    ReactDebugInstanceMap.registerInstance(inst2);
-    expect(ReactDebugInstanceMap.isRegisteredInstance(inst1)).toBe(true);
-    expect(ReactDebugInstanceMap.isRegisteredInstance(inst2)).toBe(true);
-
-    ReactDebugInstanceMap.unregisterInstance(inst2);
-    expect(ReactDebugInstanceMap.isRegisteredInstance(inst1)).toBe(true);
-    expect(ReactDebugInstanceMap.isRegisteredInstance(inst2)).toBe(false);
-
-    ReactDebugInstanceMap.unregisterInstance(inst1);
-    expect(ReactDebugInstanceMap.isRegisteredInstance(inst1)).toBe(false);
-    expect(ReactDebugInstanceMap.isRegisteredInstance(inst2)).toBe(false);
-  });
-
-  it('should assign stable IDs', function() {
-    var inst1 = createStubInstance();
-    var inst2 = createStubInstance();
-
-    var inst1ID = ReactDebugInstanceMap.getIDForInstance(inst1);
-    var inst2ID = ReactDebugInstanceMap.getIDForInstance(inst2);
-    expect(typeof inst1ID).toBe('string');
-    expect(typeof inst2ID).toBe('string');
-    expect(inst1ID).not.toBe(inst2ID);
-
-    ReactDebugInstanceMap.registerInstance(inst1);
-    ReactDebugInstanceMap.registerInstance(inst2);
-    expect(ReactDebugInstanceMap.getIDForInstance(inst1)).toBe(inst1ID);
-    expect(ReactDebugInstanceMap.getIDForInstance(inst2)).toBe(inst2ID);
-
-    ReactDebugInstanceMap.unregisterInstance(inst1);
-    ReactDebugInstanceMap.unregisterInstance(inst2);
-    expect(ReactDebugInstanceMap.getIDForInstance(inst1)).toBe(inst1ID);
-    expect(ReactDebugInstanceMap.getIDForInstance(inst2)).toBe(inst2ID);
-  });
-
-  it('should retrieve registered instance by its ID', function() {
-    var inst1 = createStubInstance();
-    var inst2 = createStubInstance();
-
-    var inst1ID = ReactDebugInstanceMap.getIDForInstance(inst1);
-    var inst2ID = ReactDebugInstanceMap.getIDForInstance(inst2);
-    expect(ReactDebugInstanceMap.getInstanceByID(inst1ID)).toBe(null);
-    expect(ReactDebugInstanceMap.getInstanceByID(inst2ID)).toBe(null);
-
-    ReactDebugInstanceMap.registerInstance(inst1);
-    ReactDebugInstanceMap.registerInstance(inst2);
-    expect(ReactDebugInstanceMap.getInstanceByID(inst1ID)).toBe(inst1);
-    expect(ReactDebugInstanceMap.getInstanceByID(inst2ID)).toBe(inst2);
-
-    ReactDebugInstanceMap.unregisterInstance(inst1);
-    ReactDebugInstanceMap.unregisterInstance(inst2);
-    expect(ReactDebugInstanceMap.getInstanceByID(inst1ID)).toBe(null);
-    expect(ReactDebugInstanceMap.getInstanceByID(inst2ID)).toBe(null);
-  });
-
-  it('should warn when registering an instance twice', function() {
-    spyOn(console, 'error');
-
-    var inst = createStubInstance();
-    ReactDebugInstanceMap.registerInstance(inst);
-    expect(console.error.argsForCall.length).toBe(0);
-
-    ReactDebugInstanceMap.registerInstance(inst);
-    expect(console.error.argsForCall.length).toBe(1);
-    expect(console.error.argsForCall[0][0]).toContain(
-      'There is an internal error in the React developer tools integration. ' +
-      'A registered instance should not be registered again. ' +
-      'Please report this as a bug in React.'
-    );
-
-    ReactDebugInstanceMap.unregisterInstance(inst);
-    ReactDebugInstanceMap.registerInstance(inst);
-    expect(console.error.argsForCall.length).toBe(1);
-  });
-
-  it('should warn when unregistering an instance twice', function() {
-    spyOn(console, 'error');
-    var inst = createStubInstance();
-
-    ReactDebugInstanceMap.unregisterInstance(inst);
-    expect(console.error.argsForCall.length).toBe(1);
-    expect(console.error.argsForCall[0][0]).toContain(
-      'There is an internal error in the React developer tools integration. ' +
-      'An unregistered instance should not be unregistered again. ' +
-      'Please report this as a bug in React.'
-    );
-
-    ReactDebugInstanceMap.registerInstance(inst);
-    ReactDebugInstanceMap.unregisterInstance(inst);
-    expect(console.error.argsForCall.length).toBe(1);
-
-    ReactDebugInstanceMap.unregisterInstance(inst);
-    expect(console.error.argsForCall.length).toBe(2);
-    expect(console.error.argsForCall[1][0]).toContain(
-      'There is an internal error in the React developer tools integration. ' +
-      'An unregistered instance should not be unregistered again. ' +
-      'Please report this as a bug in React.'
-    );
-  });
-
-  it('should warn about anything than is not an internal instance', function() {
-    class Foo extends React.Component {
-      render() {
-        return <div />;
-      }
-    }
-
-    spyOn(console, 'error');
-    var warningCount = 0;
-    var div = document.createElement('div');
-    var publicInst = ReactDOM.render(<Foo />, div);
-
-    [false, null, undefined, {}, div, publicInst].forEach(falsyValue => {
-      ReactDebugInstanceMap.registerInstance(falsyValue);
-      warningCount++;
-      expect(ReactDebugInstanceMap.getIDForInstance(falsyValue)).toBe(null);
-      warningCount++;
-      expect(ReactDebugInstanceMap.isRegisteredInstance(falsyValue)).toBe(false);
-      warningCount++;
-      ReactDebugInstanceMap.unregisterInstance(falsyValue);
-      warningCount++;
-    });
-
-    expect(console.error.argsForCall.length).toBe(warningCount);
-    for (var i = 0; i < warningCount.length; i++) {
-      // Ideally we could check for the more detailed error message here
-      // but it depends on the input type and is meant for internal bugs
-      // anyway so I don't think it's worth complicating the test with it.
-      expect(console.error.argsForCall[i][0]).toContain(
-        'There is an internal error in the React developer tools integration.'
-      );
-    }
-  });
-});
diff --git a/src/test/__tests__/ReactDefaultPerf-test.js b/src/isomorphic/__tests__/ReactPerf-test.js
similarity index 66%
rename from src/test/__tests__/ReactDefaultPerf-test.js
rename to src/isomorphic/__tests__/ReactPerf-test.js
index 8019f0fe8e..644bc618b8 100644
--- a/src/test/__tests__/ReactDefaultPerf-test.js
+++ b/src/isomorphic/__tests__/ReactPerf-test.js
@@ -11,13 +11,11 @@
 
 'use strict';
 
-describe('ReactDefaultPerf', function() {
+describe('ReactPerf', function() {
   var React;
   var ReactDOM;
-  var ReactDOMFeatureFlags;
-  var ReactDefaultPerf;
+  var ReactPerf;
   var ReactTestUtils;
-  var ReactDefaultPerfAnalysis;
 
   var App;
   var Box;
@@ -36,10 +34,8 @@ describe('ReactDefaultPerf', function() {
 
     React = require('React');
     ReactDOM = require('ReactDOM');
-    ReactDOMFeatureFlags = require('ReactDOMFeatureFlags');
-    ReactDefaultPerf = require('ReactDefaultPerf');
+    ReactPerf = require('ReactPerf');
     ReactTestUtils = require('ReactTestUtils');
-    ReactDefaultPerfAnalysis = require('ReactDefaultPerfAnalysis');
 
     App = React.createClass({
       render: function() {
@@ -68,10 +64,17 @@ describe('ReactDefaultPerf', function() {
   });
 
   function measure(fn) {
-    ReactDefaultPerf.start();
+    ReactPerf.start();
     fn();
-    ReactDefaultPerf.stop();
-    return ReactDefaultPerf.getLastMeasurements().__unstable_this_format_will_change;
+    ReactPerf.stop();
+
+    // Make sure none of the methods crash.
+    ReactPerf.getWasted();
+    ReactPerf.getInclusive();
+    ReactPerf.getExclusive();
+    ReactPerf.getOperations();
+
+    return ReactPerf.getLastMeasurements();
   }
 
   it('should count no-op update as waste', function() {
@@ -81,20 +84,18 @@ describe('ReactDefaultPerf', function() {
       ReactDOM.render(<App />, container);
     });
 
-    var summary = ReactDefaultPerf.getWasted(measurements);
-    expect(summary.length).toBe(2);
-
-    /*eslint-disable dot-notation */
-
-    expect(summary[0]['Owner > component']).toBe('<root> > App');
-    expect(summary[0]['Wasted time (ms)']).not.toBe(0);
-    expect(summary[0]['Instances']).toBe(1);
-
-    expect(summary[1]['Owner > component']).toBe('App > Box');
-    expect(summary[1]['Wasted time (ms)']).not.toBe(0);
-    expect(summary[1]['Instances']).toBe(2);
-
-    /*eslint-enable dot-notation */
+    var summary = ReactPerf.getWasted(measurements);
+    expect(summary).toEqual([{
+      key: 'App',
+      instanceCount: 1,
+      inclusiveRenderDuration: 3,
+      renderCount: 1,
+    }, {
+      key: 'App > Box',
+      instanceCount: 2,
+      inclusiveRenderDuration: 2,
+      renderCount: 2,
+    }]);
   });
 
   it('should count no-op update in child as waste', function() {
@@ -107,21 +108,18 @@ describe('ReactDefaultPerf', function() {
       ReactDOM.render(<App flipSecond={true} />, container);
     });
 
-    var summary = ReactDefaultPerf.getWasted(measurements);
-    expect(summary.length).toBe(1);
-
-    /*eslint-disable dot-notation */
-
-    expect(summary[0]['Owner > component']).toBe('App > Box');
-    expect(summary[0]['Wasted time (ms)']).not.toBe(0);
-    expect(summary[0]['Instances']).toBe(1);
-
-    /*eslint-enable dot-notation */
+    var summary = ReactPerf.getWasted(measurements);
+    expect(summary).toEqual([{
+      key: 'App > Box',
+      instanceCount: 1,
+      inclusiveRenderDuration: 1,
+      renderCount: 1,
+    }]);
   });
 
   function expectNoWaste(fn) {
     var measurements = measure(fn);
-    var summary = ReactDefaultPerf.getWasted(measurements);
+    var summary = ReactPerf.getWasted(measurements);
     expect(summary).toEqual([]);
   }
 
@@ -217,83 +215,72 @@ describe('ReactDefaultPerf', function() {
     });
   });
 
-  it('putListener should not be instrumented', function() {
+  it('should not count replacing null with a native as waste', function() {
+    var element = null;
+    function Foo() {
+      return element;
+    }
     var container = document.createElement('div');
-    ReactDOM.render(<Div onClick={function() {}}>hey</Div>, container);
-    var measurements = measure(() => {
-      ReactDOM.render(<Div onClick={function() {}}>hey</Div>, container);
-    });
-
-    var summary = ReactDefaultPerfAnalysis.getDOMSummary(measurements);
-    expect(summary).toEqual([]);
-  });
-
-  it('deleteListener should not be instrumented', function() {
-    var container = document.createElement('div');
-    ReactDOM.render(<Div onClick={function() {}}>hey</Div>, container);
-    var measurements = measure(() => {
-      ReactDOM.render(<Div>hey</Div>, container);
-    });
-
-    var summary = ReactDefaultPerfAnalysis.getDOMSummary(measurements);
-    expect(summary).toEqual([]);
-  });
-
-  it('should not fail on input change events', function() {
-    var container = document.createElement('div');
-    var onChange = () => {};
-    var input = ReactDOM.render(
-      <input checked={true} onChange={onChange} />,
-      container
-    );
+    ReactDOM.render(<Foo />, container);
     expectNoWaste(() => {
-      ReactTestUtils.Simulate.change(input);
+      element = <div />;
+      ReactDOM.render(<Foo />, container);
     });
   });
 
-  it('should print a table after calling printOperations', function() {
+  it('should not count replacing a native with null as waste', function() {
+    var element = <div />;
+    function Foo() {
+      return element;
+    }
+    var container = document.createElement('div');
+    ReactDOM.render(<Foo />, container);
+    expectNoWaste(() => {
+      element = null;
+      ReactDOM.render(<Foo />, container);
+    });
+  });
+
+  it('should include stats for components unmounted during measurement', function() {
     var container = document.createElement('div');
     var measurements = measure(() => {
-      ReactDOM.render(<Div>hey</Div>, container);
+      ReactDOM.render(<Div><Div key="a" /></Div>, container);
+      ReactDOM.render(<Div><Div key="b" /></Div>, container);
     });
-    spyOn(console, 'table');
-    ReactDefaultPerf.printOperations(measurements);
-    expect(console.table.calls.length).toBe(1);
-    expect(console.table.argsForCall[0][0]).toEqual([{
-      'data-reactid': '',
-      type: 'set innerHTML',
-      args: ReactDOMFeatureFlags.useCreateElement ?
-        '{"node":"<not serializable>","children":[],"html":null,"text":null}' :
-        '"<div data-reactroot=\\"\\" data-reactid=\\"1\\">hey</div>"',
+    expect(ReactPerf.getExclusive(measurements)).toEqual([{
+      key: 'Div',
+      instanceCount: 3,
+      counts: { ctor: 3, render: 4 },
+      durations: { ctor: 3, render: 4 },
+      totalDuration: 7,
     }]);
   });
 
   it('warns once when using getMeasurementsSummaryMap', function() {
     var measurements = measure(() => {});
     spyOn(console, 'error');
-    ReactDefaultPerf.getMeasurementsSummaryMap(measurements);
+    ReactPerf.getMeasurementsSummaryMap(measurements);
     expect(console.error.calls.length).toBe(1);
     expect(console.error.argsForCall[0][0]).toContain(
       '`ReactPerf.getMeasurementsSummaryMap(...)` is deprecated. Use ' +
       '`ReactPerf.getWasted(...)` instead.'
     );
 
-    ReactDefaultPerf.getMeasurementsSummaryMap(measurements);
+    ReactPerf.getMeasurementsSummaryMap(measurements);
     expect(console.error.calls.length).toBe(1);
   });
 
   it('warns once when using printDOM', function() {
     var measurements = measure(() => {});
     spyOn(console, 'error');
-    ReactDefaultPerf.printDOM(measurements);
+    ReactPerf.printDOM(measurements);
     expect(console.error.calls.length).toBe(1);
     expect(console.error.argsForCall[0][0]).toContain(
       '`ReactPerf.printDOM(...)` is deprecated. Use ' +
       '`ReactPerf.printOperations(...)` instead.'
     );
 
-    ReactDefaultPerf.printDOM(measurements);
+    ReactPerf.printDOM(measurements);
     expect(console.error.calls.length).toBe(1);
   });
-
 });
diff --git a/src/isomorphic/children/ReactChildren.js b/src/isomorphic/children/ReactChildren.js
index 417f78aa28..75670dbe36 100644
--- a/src/isomorphic/children/ReactChildren.js
+++ b/src/isomorphic/children/ReactChildren.js
@@ -55,6 +55,8 @@ function forEachSingleChild(bookKeeping, child, name) {
 /**
  * Iterates through children that are typically specified as `props.children`.
  *
+ * See https://facebook.github.io/react/docs/top-level-api.html#react.children.foreach
+ *
  * The provided forEachFunc(child, index) will be called for each
  * leaf child.
  *
@@ -146,7 +148,9 @@ function mapIntoWithKeyPrefixInternal(children, array, prefix, func, context) {
 /**
  * Maps children that are typically specified as `props.children`.
  *
- * The provided mapFunction(child, index) will be called for each
+ * See https://facebook.github.io/react/docs/top-level-api.html#react.children.map
+ *
+ * The provided mapFunction(child, key, index) will be called for each
  * leaf child.
  *
  * @param {?*} children Children tree container.
@@ -173,6 +177,8 @@ function forEachSingleChildDummy(traverseContext, child, name) {
  * Count the number of children that are typically specified as
  * `props.children`.
  *
+ * See https://facebook.github.io/react/docs/top-level-api.html#react.children.count
+ *
  * @param {?*} children Children tree container.
  * @return {number} The number of children.
  */
@@ -184,6 +190,8 @@ function countChildren(children, context) {
 /**
  * Flatten a children object (typically specified as `props.children`) and
  * return an array with appropriately re-keyed children.
+ *
+ * See https://facebook.github.io/react/docs/top-level-api.html#react.children.toarray
  */
 function toArray(children) {
   var result = [];
diff --git a/src/isomorphic/children/onlyChild.js b/src/isomorphic/children/onlyChild.js
index e1d3706c7e..505dea4246 100644
--- a/src/isomorphic/children/onlyChild.js
+++ b/src/isomorphic/children/onlyChild.js
@@ -16,10 +16,13 @@ var invariant = require('invariant');
 
 /**
  * Returns the first child in a collection of children and verifies that there
- * is only one child in the collection. The current implementation of this
- * function assumes that a single child gets passed without a wrapper, but the
- * purpose of this helper function is to abstract away the particular structure
- * of children.
+ * is only one child in the collection.
+ *
+ * See https://facebook.github.io/react/docs/top-level-api.html#react.children.only
+ *
+ * The current implementation of this function assumes that a single child gets
+ * passed without a wrapper, but the purpose of this helper function is to
+ * abstract away the particular structure of children.
  *
  * @param {?object} children Child collection structure.
  * @return {ReactElement} The first and only `ReactElement` contained in the
diff --git a/src/isomorphic/classic/class/ReactClass.js b/src/isomorphic/classic/class/ReactClass.js
index 56f479a42e..fe82510b89 100644
--- a/src/isomorphic/classic/class/ReactClass.js
+++ b/src/isomorphic/classic/class/ReactClass.js
@@ -740,6 +740,7 @@ var ReactClass = {
 
   /**
    * Creates a composite component class given a class specification.
+   * See https://facebook.github.io/react/docs/top-level-api.html#react.createclass
    *
    * @param {object} spec Class specification (which must define `render`).
    * @return {function} Component constructor function.
diff --git a/src/isomorphic/classic/class/__tests__/ReactBind-test.js b/src/isomorphic/classic/class/__tests__/ReactBind-test.js
index 63aa641a9c..bbf9d0c7da 100644
--- a/src/isomorphic/classic/class/__tests__/ReactBind-test.js
+++ b/src/isomorphic/classic/class/__tests__/ReactBind-test.js
@@ -20,9 +20,9 @@ describe('autobinding', function() {
 
   it('Holds reference to instance', function() {
 
-    var mouseDidEnter = jest.genMockFn();
-    var mouseDidLeave = jest.genMockFn();
-    var mouseDidClick = jest.genMockFn();
+    var mouseDidEnter = jest.fn();
+    var mouseDidLeave = jest.fn();
+    var mouseDidClick = jest.fn();
 
     var TestBindComponent = React.createClass({
       getInitialState: function() {
@@ -95,7 +95,7 @@ describe('autobinding', function() {
   });
 
   it('works with mixins', function() {
-    var mouseDidClick = jest.genMockFn();
+    var mouseDidClick = jest.fn();
 
     var TestMixin = {
       onClick: mouseDidClick,
diff --git a/src/isomorphic/classic/class/__tests__/ReactBindOptout-test.js b/src/isomorphic/classic/class/__tests__/ReactBindOptout-test.js
index 395e345770..54d3c11f5c 100644
--- a/src/isomorphic/classic/class/__tests__/ReactBindOptout-test.js
+++ b/src/isomorphic/classic/class/__tests__/ReactBindOptout-test.js
@@ -20,9 +20,9 @@ describe('autobind optout', function() {
 
   it('should work with manual binding', function() {
 
-    var mouseDidEnter = jest.genMockFn();
-    var mouseDidLeave = jest.genMockFn();
-    var mouseDidClick = jest.genMockFn();
+    var mouseDidEnter = jest.fn();
+    var mouseDidLeave = jest.fn();
+    var mouseDidClick = jest.fn();
 
     var TestBindComponent = React.createClass({
       autobind: false,
@@ -138,7 +138,7 @@ describe('autobind optout', function() {
   });
 
   it('works with mixins that have not opted out of autobinding', function() {
-    var mouseDidClick = jest.genMockFn();
+    var mouseDidClick = jest.fn();
 
     var TestMixin = {
       onClick: mouseDidClick,
@@ -164,7 +164,7 @@ describe('autobind optout', function() {
   });
 
   it('works with mixins that have opted out of autobinding', function() {
-    var mouseDidClick = jest.genMockFn();
+    var mouseDidClick = jest.fn();
 
     var TestMixin = {
       autobind: false,
diff --git a/src/isomorphic/classic/class/__tests__/ReactClass-test.js b/src/isomorphic/classic/class/__tests__/ReactClass-test.js
index 07a1e4bcb3..9a5587f7b7 100644
--- a/src/isomorphic/classic/class/__tests__/ReactClass-test.js
+++ b/src/isomorphic/classic/class/__tests__/ReactClass-test.js
@@ -43,7 +43,7 @@ describe('ReactClass-spec', function() {
   });
 
   it('should copy prop types onto the Constructor', function() {
-    var propValidator = jest.genMockFn();
+    var propValidator = jest.fn();
     var TestComponent = React.createClass({
       propTypes: {
         value: propValidator,
diff --git a/src/isomorphic/classic/class/__tests__/ReactClassMixin-test.js b/src/isomorphic/classic/class/__tests__/ReactClassMixin-test.js
index a65c68ff07..f32af1e046 100644
--- a/src/isomorphic/classic/class/__tests__/ReactClassMixin-test.js
+++ b/src/isomorphic/classic/class/__tests__/ReactClassMixin-test.js
@@ -25,8 +25,8 @@ describe('ReactClass-mixin', function() {
   beforeEach(function() {
     React = require('React');
     ReactTestUtils = require('ReactTestUtils');
-    mixinPropValidator = jest.genMockFn();
-    componentPropValidator = jest.genMockFn();
+    mixinPropValidator = jest.fn();
+    componentPropValidator = jest.fn();
 
     var MixinA = {
       propTypes: {
@@ -107,7 +107,7 @@ describe('ReactClass-mixin', function() {
   });
 
   it('should support merging propTypes and statics', function() {
-    var listener = jest.genMockFn();
+    var listener = jest.fn();
     var instance = <TestComponent listener={listener} />;
     instance = ReactTestUtils.renderIntoDocument(instance);
 
@@ -122,7 +122,7 @@ describe('ReactClass-mixin', function() {
   });
 
   it('should support chaining delegate functions', function() {
-    var listener = jest.genMockFn();
+    var listener = jest.fn();
     var instance = <TestComponent listener={listener} />;
     instance = ReactTestUtils.renderIntoDocument(instance);
 
@@ -135,7 +135,7 @@ describe('ReactClass-mixin', function() {
   });
 
   it('should chain functions regardless of spec property order', function() {
-    var listener = jest.genMockFn();
+    var listener = jest.fn();
     var instance = <TestComponentWithReverseSpec listener={listener} />;
     instance = ReactTestUtils.renderIntoDocument(instance);
 
diff --git a/src/isomorphic/classic/element/ReactElement.js b/src/isomorphic/classic/element/ReactElement.js
index ee46a5f392..40c1c7fc29 100644
--- a/src/isomorphic/classic/element/ReactElement.js
+++ b/src/isomorphic/classic/element/ReactElement.js
@@ -113,6 +113,10 @@ var ReactElement = function(type, key, ref, self, source, owner, props) {
   return element;
 };
 
+/**
+ * Create and return a new ReactElement of the given type.
+ * See https://facebook.github.io/react/docs/top-level-api.html#react.createelement
+ */
 ReactElement.createElement = function(type, config, children) {
   var propName;
 
@@ -126,6 +130,13 @@ ReactElement.createElement = function(type, config, children) {
 
   if (config != null) {
     if (__DEV__) {
+      warning(
+        /* eslint-disable no-proto */
+        config.__proto__ == null || config.__proto__ === Object.prototype,
+        /* eslint-enable no-proto */
+        'React.createElement(...): Expected props argument to be a plain object. ' +
+        'Properties defined in its prototype chain will be ignored.'
+      );
       ref = !config.hasOwnProperty('ref') ||
         Object.getOwnPropertyDescriptor(config, 'ref').get ? null : config.ref;
       key = !config.hasOwnProperty('key') ||
@@ -223,6 +234,10 @@ ReactElement.createElement = function(type, config, children) {
   );
 };
 
+/**
+ * Return a function that produces ReactElements of a given type.
+ * See https://facebook.github.io/react/docs/top-level-api.html#react.createfactory
+ */
 ReactElement.createFactory = function(type) {
   var factory = ReactElement.createElement.bind(null, type);
   // Expose the type on the factory and the prototype so that it can be
@@ -248,6 +263,10 @@ ReactElement.cloneAndReplaceKey = function(oldElement, newKey) {
   return newElement;
 };
 
+/**
+ * Clone and return a new ReactElement using element as the starting point.
+ * See https://facebook.github.io/react/docs/top-level-api.html#react.cloneelement
+ */
 ReactElement.cloneElement = function(element, config, children) {
   var propName;
 
@@ -268,6 +287,15 @@ ReactElement.cloneElement = function(element, config, children) {
   var owner = element._owner;
 
   if (config != null) {
+    if (__DEV__) {
+      warning(
+        /* eslint-disable no-proto */
+        config.__proto__ == null || config.__proto__ === Object.prototype,
+        /* eslint-enable no-proto */
+        'React.cloneElement(...): Expected props argument to be a plain object. ' +
+        'Properties defined in its prototype chain will be ignored.'
+      );
+    }
     if (config.ref !== undefined) {
       // Silently steal the ref from the parent.
       ref = config.ref;
@@ -319,6 +347,8 @@ ReactElement.cloneElement = function(element, config, children) {
 };
 
 /**
+ * Verifies the object is a ReactElement.
+ * See https://facebook.github.io/react/docs/top-level-api.html#react.isvalidelement
  * @param {?object} object
  * @return {boolean} True if `object` is a valid component.
  * @final
diff --git a/src/isomorphic/classic/element/__tests__/ReactElement-test.js b/src/isomorphic/classic/element/__tests__/ReactElement-test.js
index 402c9b95ed..8b3900db9f 100644
--- a/src/isomorphic/classic/element/__tests__/ReactElement-test.js
+++ b/src/isomorphic/classic/element/__tests__/ReactElement-test.js
@@ -138,6 +138,18 @@ describe('ReactElement', function() {
     expect(element.props.foo).toBe(1);
   });
 
+  it('warns if the config object inherits from any type other than Object', function() {
+    spyOn(console, 'error');
+    React.createElement('div', {foo: 1});
+    expect(console.error).not.toHaveBeenCalled();
+    React.createElement('div', Object.create({foo: 1}));
+    expect(console.error.argsForCall.length).toBe(1);
+    expect(console.error.argsForCall[0][0]).toContain(
+      'React.createElement(...): Expected props argument to be a plain object. ' +
+      'Properties defined in its prototype chain will be ignored.'
+    );
+  });
+
   it('extracts key and ref from the config', function() {
     var element = React.createFactory(ComponentClass)({
       key: '12',
diff --git a/src/isomorphic/classic/element/__tests__/ReactElementClone-test.js b/src/isomorphic/classic/element/__tests__/ReactElementClone-test.js
index f4c5b4b761..20b4089726 100644
--- a/src/isomorphic/classic/element/__tests__/ReactElementClone-test.js
+++ b/src/isomorphic/classic/element/__tests__/ReactElementClone-test.js
@@ -66,6 +66,18 @@ describe('ReactElementClone', function() {
     expect(ReactDOM.findDOMNode(component).childNodes[0].className).toBe('xyz');
   });
 
+  it('should warn if the config object inherits from any type other than Object', function() {
+    spyOn(console, 'error');
+    React.cloneElement('div', {foo: 1});
+    expect(console.error).not.toHaveBeenCalled();
+    React.cloneElement('div', Object.create({foo: 1}));
+    expect(console.error.argsForCall.length).toBe(1);
+    expect(console.error.argsForCall[0][0]).toContain(
+      'React.cloneElement(...): Expected props argument to be a plain object. ' +
+      'Properties defined in its prototype chain will be ignored.'
+    );
+  });
+
   it('should keep the original ref if it is not overridden', function() {
     var Grandparent = React.createClass({
       render: function() {
diff --git a/src/isomorphic/devtools/ReactComponentTreeDevtool.js b/src/isomorphic/devtools/ReactComponentTreeDevtool.js
new file mode 100644
index 0000000000..85902c30d0
--- /dev/null
+++ b/src/isomorphic/devtools/ReactComponentTreeDevtool.js
@@ -0,0 +1,163 @@
+/**
+ * Copyright 2016-present, Facebook, Inc.
+ * All rights reserved.
+ *
+ * This source code is licensed under the BSD-style license found in the
+ * LICENSE file in the root directory of this source tree. An additional grant
+ * of patent rights can be found in the PATENTS file in the same directory.
+ *
+ * @providesModule ReactComponentTreeDevtool
+ */
+
+'use strict';
+
+var invariant = require('invariant');
+
+var tree = {};
+var rootIDs = [];
+
+function updateTree(id, update) {
+  if (!tree[id]) {
+    tree[id] = {
+      parentID: null,
+      ownerID: null,
+      text: null,
+      childIDs: [],
+      displayName: 'Unknown',
+      isMounted: false,
+      updateCount: 0,
+    };
+  }
+  update(tree[id]);
+}
+
+function purgeDeep(id) {
+  var item = tree[id];
+  if (item) {
+    var {childIDs} = item;
+    delete tree[id];
+    childIDs.forEach(purgeDeep);
+  }
+}
+
+var ReactComponentTreeDevtool = {
+  onSetDisplayName(id, displayName) {
+    updateTree(id, item => item.displayName = displayName);
+  },
+
+  onSetChildren(id, nextChildIDs) {
+    updateTree(id, item => {
+      var prevChildIDs = item.childIDs;
+      item.childIDs = nextChildIDs;
+
+      nextChildIDs.forEach(nextChildID => {
+        var nextChild = tree[nextChildID];
+        invariant(
+          nextChild,
+          'Expected devtool events to fire for the child ' +
+          'before its parent includes it in onSetChildren().'
+        );
+        invariant(
+          nextChild.displayName != null,
+          'Expected onSetDisplayName() to fire for the child ' +
+          'before its parent includes it in onSetChildren().'
+        );
+        invariant(
+          nextChild.childIDs != null || nextChild.text != null,
+          'Expected onSetChildren() or onSetText() to fire for the child ' +
+          'before its parent includes it in onSetChildren().'
+        );
+        invariant(
+          nextChild.isMounted,
+          'Expected onMountComponent() to fire for the child ' +
+          'before its parent includes it in onSetChildren().'
+        );
+
+        if (prevChildIDs.indexOf(nextChildID) === -1) {
+          nextChild.parentID = id;
+        }
+      });
+    });
+  },
+
+  onSetOwner(id, ownerID) {
+    updateTree(id, item => item.ownerID = ownerID);
+  },
+
+  onSetText(id, text) {
+    updateTree(id, item => item.text = text);
+  },
+
+  onMountComponent(id) {
+    updateTree(id, item => item.isMounted = true);
+  },
+
+  onMountRootComponent(id) {
+    rootIDs.push(id);
+  },
+
+  onUpdateComponent(id) {
+    updateTree(id, item => item.updateCount++);
+  },
+
+  onUnmountComponent(id) {
+    updateTree(id, item => item.isMounted = false);
+    rootIDs = rootIDs.filter(rootID => rootID !== id);
+  },
+
+  purgeUnmountedComponents() {
+    if (ReactComponentTreeDevtool._preventPurging) {
+      // Should only be used for testing.
+      return;
+    }
+
+    Object.keys(tree)
+      .filter(id => !tree[id].isMounted)
+      .forEach(purgeDeep);
+  },
+
+  isMounted(id) {
+    var item = tree[id];
+    return item ? item.isMounted : false;
+  },
+
+  getChildIDs(id) {
+    var item = tree[id];
+    return item ? item.childIDs : [];
+  },
+
+  getDisplayName(id) {
+    var item = tree[id];
+    return item ? item.displayName : 'Unknown';
+  },
+
+  getOwnerID(id) {
+    var item = tree[id];
+    return item ? item.ownerID : null;
+  },
+
+  getParentID(id) {
+    var item = tree[id];
+    return item ? item.parentID : null;
+  },
+
+  getText(id) {
+    var item = tree[id];
+    return item ? item.text : null;
+  },
+
+  getUpdateCount(id) {
+    var item = tree[id];
+    return item ? item.updateCount : 0;
+  },
+
+  getRootIDs() {
+    return rootIDs;
+  },
+
+  getRegisteredIDs() {
+    return Object.keys(tree);
+  },
+};
+
+module.exports = ReactComponentTreeDevtool;
diff --git a/src/isomorphic/devtools/ReactNativeOperationHistoryDevtool.js b/src/isomorphic/devtools/ReactNativeOperationHistoryDevtool.js
new file mode 100644
index 0000000000..46b8194465
--- /dev/null
+++ b/src/isomorphic/devtools/ReactNativeOperationHistoryDevtool.js
@@ -0,0 +1,39 @@
+/**
+ * Copyright 2016-present, Facebook, Inc.
+ * All rights reserved.
+ *
+ * This source code is licensed under the BSD-style license found in the
+ * LICENSE file in the root directory of this source tree. An additional grant
+ * of patent rights can be found in the PATENTS file in the same directory.
+ *
+ * @providesModule ReactNativeOperationHistoryDevtool
+ */
+
+'use strict';
+
+var history = [];
+
+var ReactNativeOperationHistoryDevtool = {
+  onNativeOperation(debugID, type, payload) {
+    history.push({
+      instanceID: debugID,
+      type,
+      payload,
+    });
+  },
+
+  clearHistory() {
+    if (ReactNativeOperationHistoryDevtool._preventClearing) {
+      // Should only be used for tests.
+      return;
+    }
+
+    history = [];
+  },
+
+  getHistory() {
+    return history;
+  },
+};
+
+module.exports = ReactNativeOperationHistoryDevtool;
diff --git a/src/isomorphic/devtools/__tests__/ReactComponentTreeDevtool-test.js b/src/isomorphic/devtools/__tests__/ReactComponentTreeDevtool-test.js
new file mode 100644
index 0000000000..1c5cdb7049
--- /dev/null
+++ b/src/isomorphic/devtools/__tests__/ReactComponentTreeDevtool-test.js
@@ -0,0 +1,1744 @@
+/**
+ * Copyright 2016-present, Facebook, Inc.
+ * All rights reserved.
+ *
+ * This source code is licensed under the BSD-style license found in the
+ * LICENSE file in the root directory of this source tree. An additional grant
+ * of patent rights can be found in the PATENTS file in the same directory.
+ *
+ * @emails react-core
+ */
+
+'use strict';
+
+describe('ReactComponentTreeDevtool', () => {
+  var React;
+  var ReactDOM;
+  var ReactDOMServer;
+  var ReactInstanceMap;
+  var ReactComponentTreeDevtool;
+
+  beforeEach(() => {
+    jest.resetModuleRegistry();
+
+    React = require('React');
+    ReactDOM = require('ReactDOM');
+    ReactDOMServer = require('ReactDOMServer');
+    ReactInstanceMap = require('ReactInstanceMap');
+    ReactComponentTreeDevtool = require('ReactComponentTreeDevtool');
+  });
+
+  function getRootDisplayNames() {
+    return ReactComponentTreeDevtool.getRootIDs()
+      .map(ReactComponentTreeDevtool.getDisplayName);
+  }
+
+  function getRegisteredDisplayNames() {
+    return ReactComponentTreeDevtool.getRegisteredIDs()
+      .map(ReactComponentTreeDevtool.getDisplayName);
+  }
+
+  function getTree(rootID, options = {}) {
+    var {
+      includeOwnerDisplayName = false,
+      includeParentDisplayName = false,
+      expectedParentID = null,
+    } = options;
+
+    var result = {
+      displayName: ReactComponentTreeDevtool.getDisplayName(rootID),
+    };
+
+    var ownerID = ReactComponentTreeDevtool.getOwnerID(rootID);
+    var parentID = ReactComponentTreeDevtool.getParentID(rootID);
+    expect(parentID).toBe(expectedParentID);
+
+    if (includeParentDisplayName && parentID) {
+      result.parentDisplayName = ReactComponentTreeDevtool.getDisplayName(parentID);
+    }
+    if (includeOwnerDisplayName && ownerID) {
+      result.ownerDisplayName = ReactComponentTreeDevtool.getDisplayName(ownerID);
+    }
+
+    var childIDs = ReactComponentTreeDevtool.getChildIDs(rootID);
+    var text = ReactComponentTreeDevtool.getText(rootID);
+    if (text != null) {
+      result.text = text;
+    } else {
+      result.children = childIDs.map(childID =>
+        getTree(childID, {...options, expectedParentID: rootID })
+      );
+    }
+
+    return result;
+  }
+
+  function assertTreeMatches(pairs, options) {
+    if (!Array.isArray(pairs[0])) {
+      pairs = [pairs];
+    }
+
+    var node = document.createElement('div');
+    var currentElement;
+    var rootInstance;
+
+    class Wrapper extends React.Component {
+      render() {
+        rootInstance = ReactInstanceMap.get(this);
+        return currentElement;
+      }
+    }
+
+    function getActualTree() {
+      return getTree(rootInstance._debugID, options).children[0];
+    }
+
+    // Mount once, render updates, then unmount.
+    // Ensure the tree is correct on every step.
+    pairs.forEach(([element, expectedTree]) => {
+      currentElement = element;
+
+      // Mount a new tree or update the existing tree.
+      ReactDOM.render(<Wrapper />, node);
+      expect(getActualTree()).toEqual(expectedTree);
+
+      // Purging should have no effect
+      // on the tree we expect to see.
+      ReactComponentTreeDevtool.purgeUnmountedComponents();
+      expect(getActualTree()).toEqual(expectedTree);
+    });
+
+    // Unmounting the root node should purge
+    // the whole subtree automatically.
+    ReactDOM.unmountComponentAtNode(node);
+    expect(getActualTree()).toBe(undefined);
+    expect(getRootDisplayNames()).toEqual([]);
+    expect(getRegisteredDisplayNames()).toEqual([]);
+
+    // Server render every pair.
+    // Ensure the tree is correct on every step.
+    pairs.forEach(([element, expectedTree]) => {
+      currentElement = element;
+
+      // Rendering to string should not produce any entries
+      // because ReactDebugTool purges it when the flush ends.
+      ReactDOMServer.renderToString(<Wrapper />);
+      expect(getActualTree()).toBe(undefined);
+      expect(getRootDisplayNames()).toEqual([]);
+      expect(getRegisteredDisplayNames()).toEqual([]);
+
+      // To test it, we tell the devtool to ignore next purge
+      // so the cleanup request by ReactDebugTool is ignored.
+      // This lets us make assertions on the actual tree.
+      ReactComponentTreeDevtool._preventPurging = true;
+      ReactDOMServer.renderToString(<Wrapper />);
+      ReactComponentTreeDevtool._preventPurging = false;
+      expect(getActualTree()).toEqual(expectedTree);
+
+      // Purge manually since we skipped the automatic purge.
+      ReactComponentTreeDevtool.purgeUnmountedComponents();
+      expect(getActualTree()).toBe(undefined);
+      expect(getRootDisplayNames()).toEqual([]);
+      expect(getRegisteredDisplayNames()).toEqual([]);
+    });
+  }
+
+  describe('mount', () => {
+    it('uses displayName or Unknown for classic components', () => {
+      var Foo = React.createClass({
+        render() {
+          return null;
+        },
+      });
+      Foo.displayName = 'Bar';
+      var Baz = React.createClass({
+        render() {
+          return null;
+        },
+      });
+      var Qux = React.createClass({
+        render() {
+          return null;
+        },
+      });
+      delete Qux.displayName;
+
+      var element = <div><Foo /><Baz /><Qux /></div>;
+      var tree = {
+        displayName: 'div',
+        children: [{
+          displayName: 'Bar',
+          children: [],
+        }, {
+          displayName: 'Baz',
+          children: [],
+        }, {
+          displayName: 'Unknown',
+          children: [],
+        }],
+      };
+      assertTreeMatches([element, tree]);
+    });
+
+    it('uses displayName, name, or ReactComponent for modern components', () => {
+      class Foo extends React.Component {
+        render() {
+          return null;
+        }
+      }
+      Foo.displayName = 'Bar';
+      class Baz extends React.Component {
+        render() {
+          return null;
+        }
+      }
+      class Qux extends React.Component {
+        render() {
+          return null;
+        }
+      }
+      delete Qux.name;
+
+      var element = <div><Foo /><Baz /><Qux /></div>;
+      var tree = {
+        displayName: 'div',
+        children: [{
+          displayName: 'Bar',
+          children: [],
+        }, {
+          displayName: 'Baz',
+          children: [],
+        }, {
+          // Note: Ideally fallback name should be consistent (e.g. "Unknown")
+          displayName: 'ReactComponent',
+          children: [],
+        }],
+      };
+      assertTreeMatches([element, tree]);
+    });
+
+    it('uses displayName, name, or Object for factory components', () => {
+      function Foo() {
+        return {
+          render() {
+            return null;
+          },
+        };
+      }
+      Foo.displayName = 'Bar';
+      function Baz() {
+        return {
+          render() {
+            return null;
+          },
+        };
+      }
+      function Qux() {
+        return {
+          render() {
+            return null;
+          },
+        };
+      }
+      delete Qux.name;
+
+      var element = <div><Foo /><Baz /><Qux /></div>;
+      var tree = {
+        displayName: 'div',
+        children: [{
+          displayName: 'Bar',
+          children: [],
+        }, {
+          displayName: 'Baz',
+          children: [],
+        }, {
+          displayName: 'Unknown',
+          children: [],
+        }],
+      };
+      assertTreeMatches([element, tree]);
+    });
+
+    it('uses displayName, name, or StatelessComponent for functional components', () => {
+      function Foo() {
+        return null;
+      }
+      Foo.displayName = 'Bar';
+      function Baz() {
+        return null;
+      }
+      function Qux() {
+        return null;
+      }
+      delete Qux.name;
+
+      var element = <div><Foo /><Baz /><Qux /></div>;
+      var tree = {
+        displayName: 'div',
+        children: [{
+          displayName: 'Bar',
+          children: [],
+        }, {
+          displayName: 'Baz',
+          children: [],
+        }, {
+          displayName: 'Unknown',
+          children: [],
+        }],
+      };
+      assertTreeMatches([element, tree]);
+    });
+
+    it('reports a native tree correctly', () => {
+      var element = (
+        <div>
+          <p>
+            <span>
+              Hi!
+            </span>
+            Wow.
+          </p>
+          <hr />
+        </div>
+      );
+      var tree = {
+        displayName: 'div',
+        children: [{
+          displayName: 'p',
+          children: [{
+            displayName: 'span',
+            children: [{
+              displayName: '#text',
+              text: 'Hi!',
+            }],
+          }, {
+            displayName: '#text',
+            text: 'Wow.',
+          }],
+        }, {
+          displayName: 'hr',
+          children: [],
+        }],
+      };
+      assertTreeMatches([element, tree]);
+    });
+
+    it('reports a simple tree with composites correctly', () => {
+      class Foo extends React.Component {
+        render() {
+          return <div />;
+        }
+      }
+
+      var element = <Foo />;
+      var tree = {
+        displayName: 'Foo',
+        children: [{
+          displayName: 'div',
+          children: [],
+        }],
+      };
+      assertTreeMatches([element, tree]);
+    });
+
+    it('reports a tree with composites correctly', () => {
+      var Qux = React.createClass({
+        render() {
+          return null;
+        },
+      });
+      function Foo() {
+        return {
+          render() {
+            return <Qux />;
+          },
+        };
+      }
+      function Bar({children}) {
+        return <h1>{children}</h1>;
+      }
+      class Baz extends React.Component {
+        render() {
+          return (
+            <div>
+              <Foo />
+              <Bar>
+                <span>Hi,</span>
+                Mom
+              </Bar>
+              <a href="#">Click me.</a>
+            </div>
+          );
+        }
+      }
+
+      var element = <Baz />;
+      var tree = {
+        displayName: 'Baz',
+        children: [{
+          displayName: 'div',
+          children: [{
+            displayName: 'Foo',
+            children: [{
+              displayName: 'Qux',
+              children: [],
+            }],
+          }, {
+            displayName: 'Bar',
+            children: [{
+              displayName: 'h1',
+              children: [{
+                displayName: 'span',
+                children: [{
+                  displayName: '#text',
+                  text: 'Hi,',
+                }],
+              }, {
+                displayName: '#text',
+                text: 'Mom',
+              }],
+            }],
+          }, {
+            displayName: 'a',
+            children: [{
+              displayName: '#text',
+              text: 'Click me.',
+            }],
+          }],
+        }],
+      };
+      assertTreeMatches([element, tree]);
+    });
+
+    it('ignores null children', () => {
+      class Foo extends React.Component {
+        render() {
+          return null;
+        }
+      }
+      var element = <Foo />;
+      var tree = {
+        displayName: 'Foo',
+        children: [],
+      };
+      assertTreeMatches([element, tree]);
+    });
+
+    it('ignores false children', () => {
+      class Foo extends React.Component {
+        render() {
+          return false;
+        }
+      }
+      var element = <Foo />;
+      var tree = {
+        displayName: 'Foo',
+        children: [],
+      };
+      assertTreeMatches([element, tree]);
+    });
+
+    it('reports text nodes as children', () => {
+      var element = <div>{'1'}{2}</div>;
+      var tree = {
+        displayName: 'div',
+        children: [{
+          displayName: '#text',
+          text: '1',
+        }, {
+          displayName: '#text',
+          text: '2',
+        }],
+      };
+      assertTreeMatches([element, tree]);
+    });
+
+    it('reports a single text node as a child', () => {
+      var element = <div>{'1'}</div>;
+      var tree = {
+        displayName: 'div',
+        children: [{
+          displayName: '#text',
+          text: '1',
+        }],
+      };
+      assertTreeMatches([element, tree]);
+    });
+
+    it('reports a single number node as a child', () => {
+      var element = <div>{42}</div>;
+      var tree = {
+        displayName: 'div',
+        children: [{
+          displayName: '#text',
+          text: '42',
+        }],
+      };
+      assertTreeMatches([element, tree]);
+    });
+
+    it('reports a zero as a child', () => {
+      var element = <div>{0}</div>;
+      var tree = {
+        displayName: 'div',
+        children: [{
+          displayName: '#text',
+          text: '0',
+        }],
+      };
+      assertTreeMatches([element, tree]);
+    });
+
+    it('skips empty nodes for multiple children', () => {
+      function Foo() {
+        return <div />;
+      }
+      var element = (
+        <div>
+          {'hi'}
+          {false}
+          {42}
+          {null}
+          <Foo />
+        </div>
+      );
+      var tree = {
+        displayName: 'div',
+        children: [{
+          displayName: '#text',
+          text: 'hi',
+        }, {
+          displayName: '#text',
+          text: '42',
+        }, {
+          displayName: 'Foo',
+          children: [{
+            displayName: 'div',
+            children: [],
+          }],
+        }],
+      };
+      assertTreeMatches([element, tree]);
+    });
+
+    it('reports html content as no children', () => {
+      var element = <div dangerouslySetInnerHTML={{__html: 'Bye.'}} />;
+      var tree = {
+        displayName: 'div',
+        children: [],
+      };
+      assertTreeMatches([element, tree]);
+    });
+  });
+
+  describe('update', () => {
+    describe('native component', () => {
+      it('updates text of a single text child', () => {
+        var elementBefore = <div>Hi.</div>;
+        var treeBefore = {
+          displayName: 'div',
+          children: [{
+            displayName: '#text',
+            text: 'Hi.',
+          }],
+        };
+
+        var elementAfter = <div>Bye.</div>;
+        var treeAfter = {
+          displayName: 'div',
+          children: [{
+            displayName: '#text',
+            text: 'Bye.',
+          }],
+        };
+
+        assertTreeMatches([
+          [elementBefore, treeBefore],
+          [elementAfter, treeAfter],
+        ]);
+      });
+
+      it('updates from no children to a single text child', () => {
+        var elementBefore = <div />;
+        var treeBefore = {
+          displayName: 'div',
+          children: [],
+        };
+
+        var elementAfter = <div>Hi.</div>;
+        var treeAfter = {
+          displayName: 'div',
+          children: [{
+            displayName: '#text',
+            text: 'Hi.',
+          }],
+        };
+
+        assertTreeMatches([
+          [elementBefore, treeBefore],
+          [elementAfter, treeAfter],
+        ]);
+      });
+
+      it('updates from a single text child to no children', () => {
+        var elementBefore = <div>Hi.</div>;
+        var treeBefore = {
+          displayName: 'div',
+          children: [{
+            displayName: '#text',
+            text: 'Hi.',
+          }],
+        };
+
+        var elementAfter = <div />;
+        var treeAfter = {
+          displayName: 'div',
+          children: [],
+        };
+
+        assertTreeMatches([
+          [elementBefore, treeBefore],
+          [elementAfter, treeAfter],
+        ]);
+      });
+
+      it('updates from html content to a single text child', () => {
+        var elementBefore = <div dangerouslySetInnerHTML={{__html: 'Hi.'}} />;
+        var treeBefore = {
+          displayName: 'div',
+          children: [],
+        };
+
+        var elementAfter = <div>Hi.</div>;
+        var treeAfter = {
+          displayName: 'div',
+          children: [{
+            displayName: '#text',
+            text: 'Hi.',
+          }],
+        };
+
+        assertTreeMatches([
+          [elementBefore, treeBefore],
+          [elementAfter, treeAfter],
+        ]);
+      });
+
+      it('updates from a single text child to html content', () => {
+        var elementBefore = <div>Hi.</div>;
+        var treeBefore = {
+          displayName: 'div',
+          children: [{
+            displayName: '#text',
+            text: 'Hi.',
+          }],
+        };
+
+        var elementAfter = <div dangerouslySetInnerHTML={{__html: 'Hi.'}} />;
+        var treeAfter = {
+          displayName: 'div',
+          children: [],
+        };
+
+        assertTreeMatches([
+          [elementBefore, treeBefore],
+          [elementAfter, treeAfter],
+        ]);
+      });
+
+      it('updates from no children to multiple text children', () => {
+        var elementBefore = <div />;
+        var treeBefore = {
+          displayName: 'div',
+          children: [],
+        };
+
+        var elementAfter = <div>{'Hi.'}{'Bye.'}</div>;
+        var treeAfter = {
+          displayName: 'div',
+          children: [{
+            displayName: '#text',
+            text: 'Hi.',
+          }, {
+            displayName: '#text',
+            text: 'Bye.',
+          }],
+        };
+
+        assertTreeMatches([
+          [elementBefore, treeBefore],
+          [elementAfter, treeAfter],
+        ]);
+      });
+
+      it('updates from multiple text children to no children', () => {
+        var elementBefore = <div>{'Hi.'}{'Bye.'}</div>;
+        var treeBefore = {
+          displayName: 'div',
+          children: [{
+            displayName: '#text',
+            text: 'Hi.',
+          }, {
+            displayName: '#text',
+            text: 'Bye.',
+          }],
+        };
+
+        var elementAfter = <div />;
+        var treeAfter = {
+          displayName: 'div',
+          children: [],
+        };
+
+        assertTreeMatches([
+          [elementBefore, treeBefore],
+          [elementAfter, treeAfter],
+        ]);
+      });
+
+      it('updates from html content to multiple text children', () => {
+        var elementBefore = <div dangerouslySetInnerHTML={{__html: 'Hi.'}} />;
+        var treeBefore = {
+          displayName: 'div',
+          children: [],
+        };
+
+        var elementAfter = <div>{'Hi.'}{'Bye.'}</div>;
+        var treeAfter = {
+          displayName: 'div',
+          children: [{
+            displayName: '#text',
+            text: 'Hi.',
+          }, {
+            displayName: '#text',
+            text: 'Bye.',
+          }],
+        };
+
+        assertTreeMatches([
+          [elementBefore, treeBefore],
+          [elementAfter, treeAfter],
+        ]);
+      });
+
+      it('updates from multiple text children to html content', () => {
+        var elementBefore = <div>{'Hi.'}{'Bye.'}</div>;
+        var treeBefore = {
+          displayName: 'div',
+          children: [{
+            displayName: '#text',
+            text: 'Hi.',
+          }, {
+            displayName: '#text',
+            text: 'Bye.',
+          }],
+        };
+
+        var elementAfter = <div dangerouslySetInnerHTML={{__html: 'Hi.'}} />;
+        var treeAfter = {
+          displayName: 'div',
+          children: [],
+        };
+
+        assertTreeMatches([
+          [elementBefore, treeBefore],
+          [elementAfter, treeAfter],
+        ]);
+      });
+
+      it('updates from html content to no children', () => {
+        var elementBefore = <div dangerouslySetInnerHTML={{__html: 'Hi.'}} />;
+        var treeBefore = {
+          displayName: 'div',
+          children: [],
+        };
+
+        var elementAfter = <div />;
+        var treeAfter = {
+          displayName: 'div',
+          children: [],
+        };
+
+        assertTreeMatches([
+          [elementBefore, treeBefore],
+          [elementAfter, treeAfter],
+        ]);
+      });
+
+      it('updates from no children to html content', () => {
+        var elementBefore = <div />;
+        var treeBefore = {
+          displayName: 'div',
+          children: [],
+        };
+
+        var elementAfter = <div dangerouslySetInnerHTML={{__html: 'Hi.'}} />;
+        var treeAfter = {
+          displayName: 'div',
+          children: [],
+        };
+
+        assertTreeMatches([
+          [elementBefore, treeBefore],
+          [elementAfter, treeAfter],
+        ]);
+      });
+
+      it('updates from one text child to multiple text children', () => {
+        var elementBefore = <div>Hi.</div>;
+        var treeBefore = {
+          displayName: 'div',
+          children: [{
+            displayName: '#text',
+            text: 'Hi.',
+          }],
+        };
+
+        var elementAfter = <div>{'Hi.'}{'Bye.'}</div>;
+        var treeAfter = {
+          displayName: 'div',
+          children: [{
+            displayName: '#text',
+            text: 'Hi.',
+          }, {
+            displayName: '#text',
+            text: 'Bye.',
+          }],
+        };
+
+        assertTreeMatches([
+          [elementBefore, treeBefore],
+          [elementAfter, treeAfter],
+        ]);
+      });
+
+      it('updates from multiple text children to one text child', () => {
+        var elementBefore = <div>{'Hi.'}{'Bye.'}</div>;
+        var treeBefore = {
+          displayName: 'div',
+          children: [{
+            displayName: '#text',
+            text: 'Hi.',
+          }, {
+            displayName: '#text',
+            text: 'Bye.',
+          }],
+        };
+
+        var elementAfter = <div>Hi.</div>;
+        var treeAfter = {
+          displayName: 'div',
+          children: [{
+            displayName: '#text',
+            text: 'Hi.',
+          }],
+        };
+        assertTreeMatches([
+          [elementBefore, treeBefore],
+          [elementAfter, treeAfter],
+        ]);
+      });
+
+      it('updates text nodes when reordering', () => {
+        var elementBefore = <div>{'Hi.'}{'Bye.'}</div>;
+        var treeBefore = {
+          displayName: 'div',
+          children: [{
+            displayName: '#text',
+            text: 'Hi.',
+          }, {
+            displayName: '#text',
+            text: 'Bye.',
+          }],
+        };
+
+        var elementAfter = <div>{'Bye.'}{'Hi.'}</div>;
+        var treeAfter = {
+          displayName: 'div',
+          children: [{
+            displayName: '#text',
+            text: 'Bye.',
+          }, {
+            displayName: '#text',
+            text: 'Hi.',
+          }],
+        };
+        assertTreeMatches([
+          [elementBefore, treeBefore],
+          [elementAfter, treeAfter],
+        ]);
+      });
+
+      it('updates native nodes when reordering with keys', () => {
+        var elementBefore = (
+          <div>
+            <div key="a">Hi.</div>
+            <div key="b">Bye.</div>
+          </div>
+        );
+        var treeBefore = {
+          displayName: 'div',
+          children: [{
+            displayName: 'div',
+            children: [{
+              displayName: '#text',
+              text: 'Hi.',
+            }],
+          }, {
+            displayName: 'div',
+            children: [{
+              displayName: '#text',
+              text: 'Bye.',
+            }],
+          }],
+        };
+
+        var elementAfter = (
+          <div>
+            <div key="b">Bye.</div>
+            <div key="a">Hi.</div>
+          </div>
+        );
+        var treeAfter = {
+          displayName: 'div',
+          children: [{
+            displayName: 'div',
+            children: [{
+              displayName: '#text',
+              text: 'Bye.',
+            }],
+          }, {
+            displayName: 'div',
+            children: [{
+              displayName: '#text',
+              text: 'Hi.',
+            }],
+          }],
+        };
+
+        assertTreeMatches([
+          [elementBefore, treeBefore],
+          [elementAfter, treeAfter],
+        ]);
+      });
+
+      it('updates native nodes when reordering without keys', () => {
+        var elementBefore = (
+          <div>
+            <div>Hi.</div>
+            <div>Bye.</div>
+          </div>
+        );
+        var treeBefore = {
+          displayName: 'div',
+          children: [{
+            displayName: 'div',
+            children: [{
+              displayName: '#text',
+              text: 'Hi.',
+            }],
+          }, {
+            displayName: 'div',
+            children: [{
+              displayName: '#text',
+              text: 'Bye.',
+            }],
+          }],
+        };
+
+        var elementAfter = (
+          <div>
+            <div>Bye.</div>
+            <div>Hi.</div>
+          </div>
+        );
+        var treeAfter = {
+          displayName: 'div',
+          children: [{
+            displayName: 'div',
+            children: [{
+              displayName: '#text',
+              text: 'Bye.',
+            }],
+          }, {
+            displayName: 'div',
+            children: [{
+              displayName: '#text',
+              text: 'Hi.',
+            }],
+          }],
+        };
+
+        assertTreeMatches([
+          [elementBefore, treeBefore],
+          [elementAfter, treeAfter],
+        ]);
+      });
+
+      it('updates a single composite child of a different type', () => {
+        function Foo() {
+          return null;
+        }
+
+        function Bar() {
+          return null;
+        }
+
+        var elementBefore = <div><Foo /></div>;
+        var treeBefore = {
+          displayName: 'div',
+          children: [{
+            displayName: 'Foo',
+            children: [],
+          }],
+        };
+
+        var elementAfter = <div><Bar /></div>;
+        var treeAfter = {
+          displayName: 'div',
+          children: [{
+            displayName: 'Bar',
+            children: [],
+          }],
+        };
+
+        assertTreeMatches([
+          [elementBefore, treeBefore],
+          [elementAfter, treeAfter],
+        ]);
+      });
+
+      it('updates a single composite child of the same type', () => {
+        function Foo({ children }) {
+          return children;
+        }
+
+        var elementBefore = <div><Foo><div /></Foo></div>;
+        var treeBefore = {
+          displayName: 'div',
+          children: [{
+            displayName: 'Foo',
+            children: [{
+              displayName: 'div',
+              children: [],
+            }],
+          }],
+        };
+
+        var elementAfter = <div><Foo><span /></Foo></div>;
+        var treeAfter = {
+          displayName: 'div',
+          children: [{
+            displayName: 'Foo',
+            children: [{
+              displayName: 'span',
+              children: [],
+            }],
+          }],
+        };
+
+        assertTreeMatches([
+          [elementBefore, treeBefore],
+          [elementAfter, treeAfter],
+        ]);
+      });
+
+      it('updates from no children to a single composite child', () => {
+        function Foo() {
+          return null;
+        }
+
+        var elementBefore = <div />;
+        var treeBefore = {
+          displayName: 'div',
+          children: [],
+        };
+
+        var elementAfter = <div><Foo /></div>;
+        var treeAfter = {
+          displayName: 'div',
+          children: [{
+            displayName: 'Foo',
+            children: [],
+          }],
+        };
+
+        assertTreeMatches([
+          [elementBefore, treeBefore],
+          [elementAfter, treeAfter],
+        ]);
+      });
+
+      it('updates from a single composite child to no children', () => {
+        function Foo() {
+          return null;
+        }
+
+        var elementBefore = <div><Foo /></div>;
+        var treeBefore = {
+          displayName: 'div',
+          children: [{
+            displayName: 'Foo',
+            children: [],
+          }],
+        };
+
+        var elementAfter = <div />;
+        var treeAfter = {
+          displayName: 'div',
+          children: [],
+        };
+
+        assertTreeMatches([
+          [elementBefore, treeBefore],
+          [elementAfter, treeAfter],
+        ]);
+      });
+
+      it('updates mixed children', () => {
+        function Foo() {
+          return <div />;
+        }
+        var element1 = (
+          <div>
+            {'hi'}
+            {false}
+            {42}
+            {null}
+            <Foo />
+          </div>
+        );
+        var tree1 = {
+          displayName: 'div',
+          children: [{
+            displayName: '#text',
+            text: 'hi',
+          }, {
+            displayName: '#text',
+            text: '42',
+          }, {
+            displayName: 'Foo',
+            children: [{
+              displayName: 'div',
+              children: [],
+            }],
+          }],
+        };
+
+        var element2 = (
+          <div>
+            <Foo />
+            {false}
+            {'hi'}
+            {null}
+          </div>
+        );
+        var tree2 = {
+          displayName: 'div',
+          children: [{
+            displayName: 'Foo',
+            children: [{
+              displayName: 'div',
+              children: [],
+            }],
+          }, {
+            displayName: '#text',
+            text: 'hi',
+          }],
+        };
+
+        var element3 = (
+          <div>
+            <Foo />
+          </div>
+        );
+        var tree3 = {
+          displayName: 'div',
+          children: [{
+            displayName: 'Foo',
+            children: [{
+              displayName: 'div',
+              children: [],
+            }],
+          }],
+        };
+
+        assertTreeMatches([
+          [element1, tree1],
+          [element2, tree2],
+          [element3, tree3],
+        ]);
+      });
+    });
+
+    describe('functional component', () => {
+      it('updates with a native child', () => {
+        function Foo({ children }) {
+          return children;
+        }
+
+        var elementBefore = <Foo><div /></Foo>;
+        var treeBefore = {
+          displayName: 'Foo',
+          children: [{
+            displayName: 'div',
+            children: [],
+          }],
+        };
+
+        var elementAfter = <Foo><span /></Foo>;
+        var treeAfter = {
+          displayName: 'Foo',
+          children: [{
+            displayName: 'span',
+            children: [],
+          }],
+        };
+
+        assertTreeMatches([
+          [elementBefore, treeBefore],
+          [elementAfter, treeAfter],
+        ]);
+      });
+
+      it('updates from null to a native child', () => {
+        function Foo({ children }) {
+          return children;
+        }
+
+        var elementBefore = <Foo>{null}</Foo>;
+        var treeBefore = {
+          displayName: 'Foo',
+          children: [],
+        };
+
+        var elementAfter = <Foo><div /></Foo>;
+        var treeAfter = {
+          displayName: 'Foo',
+          children: [{
+            displayName: 'div',
+            children: [],
+          }],
+        };
+
+        assertTreeMatches([
+          [elementBefore, treeBefore],
+          [elementAfter, treeAfter],
+        ]);
+      });
+
+      it('updates from a native child to null', () => {
+        function Foo({ children }) {
+          return children;
+        }
+
+        var elementBefore = <Foo><div /></Foo>;
+        var treeBefore = {
+          displayName: 'Foo',
+          children: [{
+            displayName: 'div',
+            children: [],
+          }],
+        };
+
+        var elementAfter = <Foo>{null}</Foo>;
+        var treeAfter = {
+          displayName: 'Foo',
+          children: [],
+        };
+
+        assertTreeMatches([
+          [elementBefore, treeBefore],
+          [elementAfter, treeAfter],
+        ]);
+      });
+
+      it('updates from a native child to a composite child', () => {
+        function Bar() {
+          return null;
+        }
+
+        function Foo({ children }) {
+          return children;
+        }
+
+        var elementBefore = <Foo><div /></Foo>;
+        var treeBefore = {
+          displayName: 'Foo',
+          children: [{
+            displayName: 'div',
+            children: [],
+          }],
+        };
+
+        var elementAfter = <Foo><Bar /></Foo>;
+        var treeAfter = {
+          displayName: 'Foo',
+          children: [{
+            displayName: 'Bar',
+            children: [],
+          }],
+        };
+
+        assertTreeMatches([
+          [elementBefore, treeBefore],
+          [elementAfter, treeAfter],
+        ]);
+      });
+
+      it('updates from a composite child to a native child', () => {
+        function Bar() {
+          return null;
+        }
+
+        function Foo({ children }) {
+          return children;
+        }
+
+        var elementBefore = <Foo><Bar /></Foo>;
+        var treeBefore = {
+          displayName: 'Foo',
+          children: [{
+            displayName: 'Bar',
+            children: [],
+          }],
+        };
+
+        var elementAfter = <Foo><div /></Foo>;
+        var treeAfter = {
+          displayName: 'Foo',
+          children: [{
+            displayName: 'div',
+            children: [],
+          }],
+        };
+
+        assertTreeMatches([
+          [elementBefore, treeBefore],
+          [elementAfter, treeAfter],
+        ]);
+      });
+
+      it('updates from null to a composite child', () => {
+        function Bar() {
+          return null;
+        }
+
+        function Foo({ children }) {
+          return children;
+        }
+
+        var elementBefore = <Foo>{null}</Foo>;
+        var treeBefore = {
+          displayName: 'Foo',
+          children: [],
+        };
+
+        var elementAfter = <Foo><Bar /></Foo>;
+        var treeAfter = {
+          displayName: 'Foo',
+          children: [{
+            displayName: 'Bar',
+            children: [],
+          }],
+        };
+
+        assertTreeMatches([
+          [elementBefore, treeBefore],
+          [elementAfter, treeAfter],
+        ]);
+      });
+
+      it('updates from a composite child to null', () => {
+        function Bar() {
+          return null;
+        }
+
+        function Foo({ children }) {
+          return children;
+        }
+
+        var elementBefore = <Foo><Bar /></Foo>;
+        var treeBefore = {
+          displayName: 'Foo',
+          children: [{
+            displayName: 'Bar',
+            children: [],
+          }],
+        };
+
+        var elementAfter = <Foo>{null}</Foo>;
+        var treeAfter = {
+          displayName: 'Foo',
+          children: [],
+        };
+
+        assertTreeMatches([
+          [elementBefore, treeBefore],
+          [elementAfter, treeAfter],
+        ]);
+      });
+    });
+
+    describe('class component', () => {
+      it('updates with a native child', () => {
+        var Foo = React.createClass({
+          render() {
+            return this.props.children;
+          },
+        });
+
+        var elementBefore = <Foo><div /></Foo>;
+        var treeBefore = {
+          displayName: 'Foo',
+          children: [{
+            displayName: 'div',
+            children: [],
+          }],
+        };
+
+        var elementAfter = <Foo><span /></Foo>;
+        var treeAfter = {
+          displayName: 'Foo',
+          children: [{
+            displayName: 'span',
+            children: [],
+          }],
+        };
+
+        assertTreeMatches([
+          [elementBefore, treeBefore],
+          [elementAfter, treeAfter],
+        ]);
+      });
+
+      it('updates from null to a native child', () => {
+        var Foo = React.createClass({
+          render() {
+            return this.props.children;
+          },
+        });
+
+        var elementBefore = <Foo>{null}</Foo>;
+        var treeBefore = {
+          displayName: 'Foo',
+          children: [],
+        };
+
+        var elementAfter = <Foo><div /></Foo>;
+        var treeAfter = {
+          displayName: 'Foo',
+          children: [{
+            displayName: 'div',
+            children: [],
+          }],
+        };
+
+        assertTreeMatches([
+          [elementBefore, treeBefore],
+          [elementAfter, treeAfter],
+        ]);
+      });
+
+      it('updates from a native child to null', () => {
+        var Foo = React.createClass({
+          render() {
+            return this.props.children;
+          },
+        });
+
+        var elementBefore = <Foo><div /></Foo>;
+        var treeBefore = {
+          displayName: 'Foo',
+          children: [{
+            displayName: 'div',
+            children: [],
+          }],
+        };
+
+        var elementAfter = <Foo>{null}</Foo>;
+        var treeAfter = {
+          displayName: 'Foo',
+          children: [],
+        };
+
+        assertTreeMatches([
+          [elementBefore, treeBefore],
+          [elementAfter, treeAfter],
+        ]);
+      });
+
+      it('updates from a native child to a composite child', () => {
+        var Bar = React.createClass({
+          render() {
+            return null;
+          },
+        });
+
+        var Foo = React.createClass({
+          render() {
+            return this.props.children;
+          },
+        });
+
+        var elementBefore = <Foo><div /></Foo>;
+        var treeBefore = {
+          displayName: 'Foo',
+          children: [{
+            displayName: 'div',
+            children: [],
+          }],
+        };
+
+        var elementAfter = <Foo><Bar /></Foo>;
+        var treeAfter = {
+          displayName: 'Foo',
+          children: [{
+            displayName: 'Bar',
+            children: [],
+          }],
+        };
+
+        assertTreeMatches([
+          [elementBefore, treeBefore],
+          [elementAfter, treeAfter],
+        ]);
+      });
+
+      it('updates from a composite child to a native child', () => {
+        var Bar = React.createClass({
+          render() {
+            return null;
+          },
+        });
+
+        var Foo = React.createClass({
+          render() {
+            return this.props.children;
+          },
+        });
+
+        var elementBefore = <Foo><Bar /></Foo>;
+        var treeBefore = {
+          displayName: 'Foo',
+          children: [{
+            displayName: 'Bar',
+            children: [],
+          }],
+        };
+
+        var elementAfter = <Foo><div /></Foo>;
+        var treeAfter = {
+          displayName: 'Foo',
+          children: [{
+            displayName: 'div',
+            children: [],
+          }],
+        };
+
+        assertTreeMatches([
+          [elementBefore, treeBefore],
+          [elementAfter, treeAfter],
+        ]);
+      });
+
+      it('updates from null to a composite child', () => {
+        var Bar = React.createClass({
+          render() {
+            return null;
+          },
+        });
+
+        var Foo = React.createClass({
+          render() {
+            return this.props.children;
+          },
+        });
+
+        var elementBefore = <Foo>{null}</Foo>;
+        var treeBefore = {
+          displayName: 'Foo',
+          children: [],
+        };
+
+        var elementAfter = <Foo><Bar /></Foo>;
+        var treeAfter = {
+          displayName: 'Foo',
+          children: [{
+            displayName: 'Bar',
+            children: [],
+          }],
+        };
+
+        assertTreeMatches([
+          [elementBefore, treeBefore],
+          [elementAfter, treeAfter],
+        ]);
+      });
+
+      it('updates from a composite child to null', () => {
+        var Bar = React.createClass({
+          render() {
+            return null;
+          },
+        });
+
+        var Foo = React.createClass({
+          render() {
+            return this.props.children;
+          },
+        });
+
+        var elementBefore = <Foo><Bar /></Foo>;
+        var treeBefore = {
+          displayName: 'Foo',
+          children: [{
+            displayName: 'Bar',
+            children: [],
+          }],
+        };
+
+        var elementAfter = <Foo>{null}</Foo>;
+        var treeAfter = {
+          displayName: 'Foo',
+          children: [],
+        };
+
+        assertTreeMatches([
+          [elementBefore, treeBefore],
+          [elementAfter, treeAfter],
+        ]);
+      });
+    });
+  });
+
+  it('tracks owner correctly', () => {
+    class Foo extends React.Component {
+      render() {
+        return <Bar><h1>Hi.</h1></Bar>;
+      }
+    }
+    function Bar({children}) {
+      return <div>{children} Mom</div>;
+    }
+
+    // Note that owner is not calculated for text nodes
+    // because they are not created from real elements.
+    var element = <article><Foo /></article>;
+    var tree = {
+      displayName: 'article',
+      children: [{
+        displayName: 'Foo',
+        children: [{
+          displayName: 'Bar',
+          ownerDisplayName: 'Foo',
+          children: [{
+            displayName: 'div',
+            ownerDisplayName: 'Bar',
+            children: [{
+              displayName: 'h1',
+              ownerDisplayName: 'Foo',
+              children: [{
+                displayName: '#text',
+                text: 'Hi.',
+              }],
+            }, {
+              displayName: '#text',
+              text: ' Mom',
+            }],
+          }],
+        }],
+      }],
+    };
+    assertTreeMatches([element, tree], {includeOwnerDisplayName: true});
+  });
+
+  it('purges unmounted components automatically', () => {
+    var node = document.createElement('div');
+    var renderBar = true;
+    var fooInstance;
+    var barInstance;
+
+    class Foo extends React.Component {
+      render() {
+        fooInstance = ReactInstanceMap.get(this);
+        return renderBar ? <Bar /> : null;
+      }
+    }
+
+    class Bar extends React.Component {
+      render() {
+        barInstance = ReactInstanceMap.get(this);
+        return null;
+      }
+    }
+
+    ReactDOM.render(<Foo />, node);
+    expect(
+      getTree(barInstance._debugID, {
+        includeParentDisplayName: true,
+        expectedParentID: fooInstance._debugID,
+      })
+    ).toEqual({
+      displayName: 'Bar',
+      parentDisplayName: 'Foo',
+      children: [],
+    });
+
+    renderBar = false;
+    ReactDOM.render(<Foo />, node);
+    expect(
+      getTree(barInstance._debugID, {expectedParentID: null})
+    ).toEqual({
+      displayName: 'Unknown',
+      children: [],
+    });
+
+    ReactDOM.unmountComponentAtNode(node);
+    expect(
+      getTree(barInstance._debugID, {expectedParentID: null})
+    ).toEqual({
+      displayName: 'Unknown',
+      children: [],
+    });
+  });
+
+  it('reports update counts', () => {
+    var node = document.createElement('div');
+
+    ReactDOM.render(<div className="a" />, node);
+    var divID = ReactComponentTreeDevtool.getRootIDs()[0];
+    expect(ReactComponentTreeDevtool.getUpdateCount(divID)).toEqual(0);
+
+    ReactDOM.render(<span className="a" />, node);
+    var spanID = ReactComponentTreeDevtool.getRootIDs()[0];
+    expect(ReactComponentTreeDevtool.getUpdateCount(divID)).toEqual(0);
+    expect(ReactComponentTreeDevtool.getUpdateCount(spanID)).toEqual(0);
+
+    ReactDOM.render(<span className="b" />, node);
+    expect(ReactComponentTreeDevtool.getUpdateCount(divID)).toEqual(0);
+    expect(ReactComponentTreeDevtool.getUpdateCount(spanID)).toEqual(1);
+
+    ReactDOM.render(<span className="c" />, node);
+    expect(ReactComponentTreeDevtool.getUpdateCount(divID)).toEqual(0);
+    expect(ReactComponentTreeDevtool.getUpdateCount(spanID)).toEqual(2);
+
+    ReactDOM.unmountComponentAtNode(node);
+    expect(ReactComponentTreeDevtool.getUpdateCount(divID)).toEqual(0);
+    expect(ReactComponentTreeDevtool.getUpdateCount(spanID)).toEqual(0);
+  });
+
+  it('does not report top-level wrapper as a root', () => {
+    var node = document.createElement('div');
+
+    ReactDOM.render(<div className="a" />, node);
+    expect(getRootDisplayNames()).toEqual(['div']);
+
+    ReactDOM.render(<div className="b" />, node);
+    expect(getRootDisplayNames()).toEqual(['div']);
+
+    ReactDOM.unmountComponentAtNode(node);
+    expect(getRootDisplayNames()).toEqual([]);
+    expect(getRegisteredDisplayNames()).toEqual([]);
+  });
+});
diff --git a/src/isomorphic/devtools/__tests__/ReactComponentTreeDevtool-test.native.js b/src/isomorphic/devtools/__tests__/ReactComponentTreeDevtool-test.native.js
new file mode 100644
index 0000000000..f3b026b459
--- /dev/null
+++ b/src/isomorphic/devtools/__tests__/ReactComponentTreeDevtool-test.native.js
@@ -0,0 +1,1716 @@
+/**
+ * Copyright 2016-present, Facebook, Inc.
+ * All rights reserved.
+ *
+ * This source code is licensed under the BSD-style license found in the
+ * LICENSE file in the root directory of this source tree. An additional grant
+ * of patent rights can be found in the PATENTS file in the same directory.
+ *
+ * @emails react-core
+ */
+
+'use strict';
+
+describe('ReactComponentTreeDevtool', () => {
+  var React;
+  var ReactNative;
+  var ReactInstanceMap;
+  var ReactComponentTreeDevtool;
+  var createReactNativeComponentClass;
+  var View;
+  var Image;
+  var Text;
+
+  beforeEach(() => {
+    jest.resetModuleRegistry();
+
+    React = require('React');
+    ReactNative = require('ReactNative');
+    ReactInstanceMap = require('ReactInstanceMap');
+    ReactComponentTreeDevtool = require('ReactComponentTreeDevtool');
+    View = require('View');
+    createReactNativeComponentClass = require('createReactNativeComponentClass');
+    Image = createReactNativeComponentClass({
+      validAttributes: {},
+      uiViewClassName: 'Image',
+    });
+    var RCText = createReactNativeComponentClass({
+      validAttributes: {},
+      uiViewClassName: 'RCText',
+    });
+    Text = React.createClass({
+      childContextTypes: {
+        isInAParentText: React.PropTypes.bool,
+      },
+      getChildContext() {
+        return {isInAParentText: true};
+      },
+      render() {
+        return <RCText {...this.props} />;
+      },
+    });
+  });
+
+  function getRootDisplayNames() {
+    return ReactComponentTreeDevtool.getRootIDs()
+      .map(ReactComponentTreeDevtool.getDisplayName);
+  }
+
+  function getRegisteredDisplayNames() {
+    return ReactComponentTreeDevtool.getRegisteredIDs()
+      .map(ReactComponentTreeDevtool.getDisplayName);
+  }
+
+  function getTree(rootID, options = {}) {
+    var {
+      includeOwnerDisplayName = false,
+      includeParentDisplayName = false,
+      expectedParentID = null,
+    } = options;
+
+    var result = {
+      displayName: ReactComponentTreeDevtool.getDisplayName(rootID),
+    };
+
+    var ownerID = ReactComponentTreeDevtool.getOwnerID(rootID);
+    var parentID = ReactComponentTreeDevtool.getParentID(rootID);
+    expect(parentID).toBe(expectedParentID);
+
+    if (includeParentDisplayName && parentID) {
+      result.parentDisplayName = ReactComponentTreeDevtool.getDisplayName(parentID);
+    }
+    if (includeOwnerDisplayName && ownerID) {
+      result.ownerDisplayName = ReactComponentTreeDevtool.getDisplayName(ownerID);
+    }
+
+    var childIDs = ReactComponentTreeDevtool.getChildIDs(rootID);
+    var text = ReactComponentTreeDevtool.getText(rootID);
+    if (text != null) {
+      result.text = text;
+    } else {
+      result.children = childIDs.map(childID =>
+        getTree(childID, {...options, expectedParentID: rootID })
+      );
+    }
+
+    return result;
+  }
+
+  function assertTreeMatches(pairs, options) {
+    if (!Array.isArray(pairs[0])) {
+      pairs = [pairs];
+    }
+
+    var currentElement;
+    var rootInstance;
+
+    class Wrapper extends React.Component {
+      render() {
+        rootInstance = ReactInstanceMap.get(this);
+        return currentElement;
+      }
+    }
+
+    function getActualTree() {
+      return getTree(rootInstance._debugID, options).children[0];
+    }
+
+    // Mount once, render updates, then unmount.
+    // Ensure the tree is correct on every step.
+    pairs.forEach(([element, expectedTree]) => {
+      currentElement = element;
+
+      // Mount a new tree or update the existing tree.
+      ReactNative.render(<Wrapper />, 1);
+      expect(getActualTree()).toEqual(expectedTree);
+
+      // Purging should have no effect
+      // on the tree we expect to see.
+      ReactComponentTreeDevtool.purgeUnmountedComponents();
+      expect(getActualTree()).toEqual(expectedTree);
+    });
+
+    // Unmounting the root node should purge
+    // the whole subtree automatically.
+    ReactNative.unmountComponentAtNode(1);
+    expect(getActualTree()).toBe(undefined);
+    expect(getRootDisplayNames()).toEqual([]);
+    expect(getRegisteredDisplayNames()).toEqual([]);
+
+    // Mount and unmount for every pair.
+    // Ensure the tree is correct on every step.
+    pairs.forEach(([element, expectedTree]) => {
+      currentElement = element;
+
+      // Mount a new tree.
+      ReactNative.render(<Wrapper />, 1);
+      expect(getActualTree()).toEqual(expectedTree);
+
+      // Unmounting should clean it up.
+      ReactNative.unmountComponentAtNode(1);
+      expect(getActualTree()).toBe(undefined);
+      expect(getRootDisplayNames()).toEqual([]);
+      expect(getRegisteredDisplayNames()).toEqual([]);
+    });
+  }
+
+  describe('mount', () => {
+    it('uses displayName or Unknown for classic components', () => {
+      var Foo = React.createClass({
+        render() {
+          return null;
+        },
+      });
+      Foo.displayName = 'Bar';
+      var Baz = React.createClass({
+        render() {
+          return null;
+        },
+      });
+      var Qux = React.createClass({
+        render() {
+          return null;
+        },
+      });
+      delete Qux.displayName;
+
+      var element = <View><Foo /><Baz /><Qux /></View>;
+      var tree = {
+        displayName: 'View',
+        children: [{
+          displayName: 'Bar',
+          children: [],
+        }, {
+          displayName: 'Baz',
+          children: [],
+        }, {
+          displayName: 'Unknown',
+          children: [],
+        }],
+      };
+      assertTreeMatches([element, tree]);
+    });
+
+    it('uses displayName, name, or ReactComponent for modern components', () => {
+      class Foo extends React.Component {
+        render() {
+          return null;
+        }
+      }
+      Foo.displayName = 'Bar';
+      class Baz extends React.Component {
+        render() {
+          return null;
+        }
+      }
+      class Qux extends React.Component {
+        render() {
+          return null;
+        }
+      }
+      delete Qux.name;
+
+      var element = <View><Foo /><Baz /><Qux /></View>;
+      var tree = {
+        displayName: 'View',
+        children: [{
+          displayName: 'Bar',
+          children: [],
+        }, {
+          displayName: 'Baz',
+          children: [],
+        }, {
+          // Note: Ideally fallback name should be consistent (e.g. "Unknown")
+          displayName: 'ReactComponent',
+          children: [],
+        }],
+      };
+      assertTreeMatches([element, tree]);
+    });
+
+    it('uses displayName, name, or Object for factory components', () => {
+      function Foo() {
+        return {
+          render() {
+            return null;
+          },
+        };
+      }
+      Foo.displayName = 'Bar';
+      function Baz() {
+        return {
+          render() {
+            return null;
+          },
+        };
+      }
+      function Qux() {
+        return {
+          render() {
+            return null;
+          },
+        };
+      }
+      delete Qux.name;
+
+      var element = <View><Foo /><Baz /><Qux /></View>;
+      var tree = {
+        displayName: 'View',
+        children: [{
+          displayName: 'Bar',
+          children: [],
+        }, {
+          displayName: 'Baz',
+          children: [],
+        }, {
+          displayName: 'Unknown',
+          children: [],
+        }],
+      };
+      assertTreeMatches([element, tree]);
+    });
+
+    it('uses displayName, name, or StatelessComponent for functional components', () => {
+      function Foo() {
+        return null;
+      }
+      Foo.displayName = 'Bar';
+      function Baz() {
+        return null;
+      }
+      function Qux() {
+        return null;
+      }
+      delete Qux.name;
+
+      var element = <View><Foo /><Baz /><Qux /></View>;
+      var tree = {
+        displayName: 'View',
+        children: [{
+          displayName: 'Bar',
+          children: [],
+        }, {
+          displayName: 'Baz',
+          children: [],
+        }, {
+          displayName: 'Unknown',
+          children: [],
+        }],
+      };
+      assertTreeMatches([element, tree]);
+    });
+
+    it('reports a native tree correctly', () => {
+      var element = (
+        <View>
+          <View>
+            <Text>
+              Hi!
+            </Text>
+          </View>
+          <Image />
+        </View>
+      );
+      var tree = {
+        displayName: 'View',
+        children: [{
+          displayName: 'View',
+          children: [{
+            displayName: 'Text',
+            children: [{
+              displayName: 'RCText',
+              children: [{
+                displayName: '#text',
+                text: 'Hi!',
+              }],
+            }],
+          }],
+        }, {
+          displayName: 'Image',
+          children: [],
+        }],
+      };
+      assertTreeMatches([element, tree]);
+    });
+
+    it('reports a simple tree with composites correctly', () => {
+      class Foo extends React.Component {
+        render() {
+          return <Image />;
+        }
+      }
+
+      var element = <Foo />;
+      var tree = {
+        displayName: 'Foo',
+        children: [{
+          displayName: 'Image',
+          children: [],
+        }],
+      };
+      assertTreeMatches([element, tree]);
+    });
+
+    it('reports a tree with composites correctly', () => {
+      var Qux = React.createClass({
+        render() {
+          return null;
+        },
+      });
+      function Foo() {
+        return {
+          render() {
+            return <Qux />;
+          },
+        };
+      }
+      function Bar({children}) {
+        return <View>{children}</View>;
+      }
+      class Baz extends React.Component {
+        render() {
+          return (
+            <View>
+              <Foo />
+              <Bar>
+                <Text>Hi,</Text>
+              </Bar>
+              <Image />
+            </View>
+          );
+        }
+      }
+
+      var element = <Baz />;
+      var tree = {
+        displayName: 'Baz',
+        children: [{
+          displayName: 'View',
+          children: [{
+            displayName: 'Foo',
+            children: [{
+              displayName: 'Qux',
+              children: [],
+            }],
+          }, {
+            displayName: 'Bar',
+            children: [{
+              displayName: 'View',
+              children: [{
+                displayName: 'Text',
+                children: [{
+                  displayName: 'RCText',
+                  children: [{
+                    displayName: '#text',
+                    text: 'Hi,',
+                  }],
+                }],
+              }],
+            }],
+          }, {
+            displayName: 'Image',
+            children: [],
+          }],
+        }],
+      };
+      assertTreeMatches([element, tree]);
+    });
+
+    it('ignores null children', () => {
+      class Foo extends React.Component {
+        render() {
+          return null;
+        }
+      }
+      var element = <Foo />;
+      var tree = {
+        displayName: 'Foo',
+        children: [],
+      };
+      assertTreeMatches([element, tree]);
+    });
+
+    it('ignores false children', () => {
+      class Foo extends React.Component {
+        render() {
+          return false;
+        }
+      }
+      var element = <Foo />;
+      var tree = {
+        displayName: 'Foo',
+        children: [],
+      };
+      assertTreeMatches([element, tree]);
+    });
+
+    it('reports text nodes as children', () => {
+      var element = <Text>{'1'}{2}</Text>;
+      var tree = {
+        displayName: 'Text',
+        children: [{
+          displayName: 'RCText',
+          children: [{
+            displayName: '#text',
+            text: '1',
+          }, {
+            displayName: '#text',
+            text: '2',
+          }],
+        }],
+      };
+      assertTreeMatches([element, tree]);
+    });
+
+    it('reports a single text node as a child', () => {
+      var element = <Text>{'1'}</Text>;
+      var tree = {
+        displayName: 'Text',
+        children: [{
+          displayName: 'RCText',
+          children: [{
+            displayName: '#text',
+            text: '1',
+          }],
+        }],
+      };
+      assertTreeMatches([element, tree]);
+    });
+
+    it('reports a single number node as a child', () => {
+      var element = <Text>{42}</Text>;
+      var tree = {
+        displayName: 'Text',
+        children: [{
+          displayName: 'RCText',
+          children: [{
+            displayName: '#text',
+            text: '42',
+          }],
+        }],
+      };
+      assertTreeMatches([element, tree]);
+    });
+
+    it('reports a zero as a child', () => {
+      var element = <Text>{0}</Text>;
+      var tree = {
+        displayName: 'Text',
+        children: [{
+          displayName: 'RCText',
+          children: [{
+            displayName: '#text',
+            text: '0',
+          }],
+        }],
+      };
+      assertTreeMatches([element, tree]);
+    });
+
+    it('skips empty nodes for multiple children', () => {
+      function Foo() {
+        return <Image />;
+      }
+      var element = (
+        <View>
+          {false}
+          <Foo />
+          {null}
+          <Foo />
+        </View>
+      );
+      var tree = {
+        displayName: 'View',
+        children: [{
+          displayName: 'Foo',
+          children: [{
+            displayName: 'Image',
+            children: [],
+          }],
+        }, {
+          displayName: 'Foo',
+          children: [{
+            displayName: 'Image',
+            children: [],
+          }],
+        }],
+      };
+      assertTreeMatches([element, tree]);
+    });
+  });
+
+  describe('update', () => {
+    describe('native component', () => {
+      it('updates text of a single text child', () => {
+        var elementBefore = <Text>Hi.</Text>;
+        var treeBefore = {
+          displayName: 'Text',
+          children: [{
+            displayName: 'RCText',
+            children: [{
+              displayName: '#text',
+              text: 'Hi.',
+            }],
+          }],
+        };
+
+        var elementAfter = <Text>Bye.</Text>;
+        var treeAfter = {
+          displayName: 'Text',
+          children: [{
+            displayName: 'RCText',
+            children: [{
+              displayName: '#text',
+              text: 'Bye.',
+            }],
+          }],
+        };
+
+        assertTreeMatches([
+          [elementBefore, treeBefore],
+          [elementAfter, treeAfter],
+        ]);
+      });
+
+      it('updates from no children to a single text child', () => {
+        var elementBefore = <Text />;
+        var treeBefore = {
+          displayName: 'Text',
+          children: [{
+            displayName: 'RCText',
+            children: [],
+          }],
+        };
+
+        var elementAfter = <Text>Hi.</Text>;
+        var treeAfter = {
+          displayName: 'Text',
+          children: [{
+            displayName: 'RCText',
+            children: [{
+              displayName: '#text',
+              text: 'Hi.',
+            }],
+          }],
+        };
+
+        assertTreeMatches([
+          [elementBefore, treeBefore],
+          [elementAfter, treeAfter],
+        ]);
+      });
+
+      it('updates from a single text child to no children', () => {
+        var elementBefore = <Text>Hi.</Text>;
+        var treeBefore = {
+          displayName: 'Text',
+          children: [{
+            displayName: 'RCText',
+            children: [{
+              displayName: '#text',
+              text: 'Hi.',
+            }],
+          }],
+        };
+
+        var elementAfter = <Text />;
+        var treeAfter = {
+          displayName: 'Text',
+          children: [{
+            displayName: 'RCText',
+            children: [],
+          }],
+        };
+
+        assertTreeMatches([
+          [elementBefore, treeBefore],
+          [elementAfter, treeAfter],
+        ]);
+      });
+
+      it('updates from no children to multiple text children', () => {
+        var elementBefore = <Text />;
+        var treeBefore = {
+          displayName: 'Text',
+          children: [{
+            displayName: 'RCText',
+            children: [],
+          }],
+        };
+
+        var elementAfter = <Text>{'Hi.'}{'Bye.'}</Text>;
+        var treeAfter = {
+          displayName: 'Text',
+          children: [{
+            displayName: 'RCText',
+            children: [{
+              displayName: '#text',
+              text: 'Hi.',
+            }, {
+              displayName: '#text',
+              text: 'Bye.',
+            }],
+          }],
+        };
+
+        assertTreeMatches([
+          [elementBefore, treeBefore],
+          [elementAfter, treeAfter],
+        ]);
+      });
+
+      it('updates from multiple text children to no children', () => {
+        var elementBefore = <Text>{'Hi.'}{'Bye.'}</Text>;
+        var treeBefore = {
+          displayName: 'Text',
+          children: [{
+            displayName: 'RCText',
+            children: [{
+              displayName: '#text',
+              text: 'Hi.',
+            }, {
+              displayName: '#text',
+              text: 'Bye.',
+            }],
+          }],
+        };
+
+        var elementAfter = <Text />;
+        var treeAfter = {
+          displayName: 'Text',
+          children: [{
+            displayName: 'RCText',
+            children: [],
+          }],
+        };
+        assertTreeMatches([
+          [elementBefore, treeBefore],
+          [elementAfter, treeAfter],
+        ]);
+      });
+
+      it('updates from one text child to multiple text children', () => {
+        var elementBefore = <Text>Hi.</Text>;
+        var treeBefore = {
+          displayName: 'Text',
+          children: [{
+            displayName: 'RCText',
+            children: [{
+              displayName: '#text',
+              text: 'Hi.',
+            }],
+          }],
+        };
+
+        var elementAfter = <Text>{'Hi.'}{'Bye.'}</Text>;
+        var treeAfter = {
+          displayName: 'Text',
+          children: [{
+            displayName: 'RCText',
+            children: [{
+              displayName: '#text',
+              text: 'Hi.',
+            }, {
+              displayName: '#text',
+              text: 'Bye.',
+            }],
+          }],
+        };
+
+        assertTreeMatches([
+          [elementBefore, treeBefore],
+          [elementAfter, treeAfter],
+        ]);
+      });
+
+      it('updates from multiple text children to one text child', () => {
+        var elementBefore = <Text>{'Hi.'}{'Bye.'}</Text>;
+        var treeBefore = {
+          displayName: 'Text',
+          children: [{
+            displayName: 'RCText',
+            children: [{
+              displayName: '#text',
+              text: 'Hi.',
+            }, {
+              displayName: '#text',
+              text: 'Bye.',
+            }],
+          }],
+        };
+
+        var elementAfter = <Text>Hi.</Text>;
+        var treeAfter = {
+          displayName: 'Text',
+          children: [{
+            displayName: 'RCText',
+            children: [{
+              displayName: '#text',
+              text: 'Hi.',
+            }],
+          }],
+        };
+        assertTreeMatches([
+          [elementBefore, treeBefore],
+          [elementAfter, treeAfter],
+        ]);
+      });
+
+      it('updates text nodes when reordering', () => {
+        var elementBefore = <Text>{'Hi.'}{'Bye.'}</Text>;
+        var treeBefore = {
+          displayName: 'Text',
+          children: [{
+            displayName: 'RCText',
+            children: [{
+              displayName: '#text',
+              text: 'Hi.',
+            }, {
+              displayName: '#text',
+              text: 'Bye.',
+            }],
+          }],
+        };
+
+        var elementAfter = <Text>{'Bye.'}{'Hi.'}</Text>;
+        var treeAfter = {
+          displayName: 'Text',
+          children: [{
+            displayName: 'RCText',
+            children: [{
+              displayName: '#text',
+              text: 'Bye.',
+            }, {
+              displayName: '#text',
+              text: 'Hi.',
+            }],
+          }],
+        };
+        assertTreeMatches([
+          [elementBefore, treeBefore],
+          [elementAfter, treeAfter],
+        ]);
+      });
+
+      it('updates native nodes when reordering with keys', () => {
+        var elementBefore = (
+          <View>
+            <Text key="a">Hi.</Text>
+            <Text key="b">Bye.</Text>
+          </View>
+        );
+        var treeBefore = {
+          displayName: 'View',
+          children: [{
+            displayName: 'Text',
+            children: [{
+              displayName: 'RCText',
+              children: [{
+                displayName: '#text',
+                text: 'Hi.',
+              }],
+            }],
+          }, {
+            displayName: 'Text',
+            children: [{
+              displayName: 'RCText',
+              children: [{
+                displayName: '#text',
+                text: 'Bye.',
+              }],
+            }],
+          }],
+        };
+
+        var elementAfter = (
+          <View>
+            <Text key="b">Bye.</Text>
+            <Text key="a">Hi.</Text>
+          </View>
+        );
+        var treeAfter = {
+          displayName: 'View',
+          children: [{
+            displayName: 'Text',
+            children: [{
+              displayName: 'RCText',
+              children: [{
+                displayName: '#text',
+                text: 'Bye.',
+              }],
+            }],
+          }, {
+            displayName: 'Text',
+            children: [{
+              displayName: 'RCText',
+              children: [{
+                displayName: '#text',
+                text: 'Hi.',
+              }],
+            }],
+          }],
+        };
+
+        assertTreeMatches([
+          [elementBefore, treeBefore],
+          [elementAfter, treeAfter],
+        ]);
+      });
+
+      it('updates native nodes when reordering with keys', () => {
+        var elementBefore = (
+          <View>
+            <Text>Hi.</Text>
+            <Text>Bye.</Text>
+          </View>
+        );
+        var treeBefore = {
+          displayName: 'View',
+          children: [{
+            displayName: 'Text',
+            children: [{
+              displayName: 'RCText',
+              children: [{
+                displayName: '#text',
+                text: 'Hi.',
+              }],
+            }],
+          }, {
+            displayName: 'Text',
+            children: [{
+              displayName: 'RCText',
+              children: [{
+                displayName: '#text',
+                text: 'Bye.',
+              }],
+            }],
+          }],
+        };
+
+        var elementAfter = (
+          <View>
+            <Text>Bye.</Text>
+            <Text>Hi.</Text>
+          </View>
+        );
+        var treeAfter = {
+          displayName: 'View',
+          children: [{
+            displayName: 'Text',
+            children: [{
+              displayName: 'RCText',
+              children: [{
+                displayName: '#text',
+                text: 'Bye.',
+              }],
+            }],
+          }, {
+            displayName: 'Text',
+            children: [{
+              displayName: 'RCText',
+              children: [{
+                displayName: '#text',
+                text: 'Hi.',
+              }],
+            }],
+          }],
+        };
+
+        assertTreeMatches([
+          [elementBefore, treeBefore],
+          [elementAfter, treeAfter],
+        ]);
+      });
+
+      it('updates a single composite child of a different type', () => {
+        function Foo() {
+          return null;
+        }
+
+        function Bar() {
+          return null;
+        }
+
+        var elementBefore = <View><Foo /></View>;
+        var treeBefore = {
+          displayName: 'View',
+          children: [{
+            displayName: 'Foo',
+            children: [],
+          }],
+        };
+
+        var elementAfter = <View><Bar /></View>;
+        var treeAfter = {
+          displayName: 'View',
+          children: [{
+            displayName: 'Bar',
+            children: [],
+          }],
+        };
+
+        assertTreeMatches([
+          [elementBefore, treeBefore],
+          [elementAfter, treeAfter],
+        ]);
+      });
+
+      it('updates a single composite child of the same type', () => {
+        function Foo({ children }) {
+          return children;
+        }
+
+        var elementBefore = <View><Foo><View /></Foo></View>;
+        var treeBefore = {
+          displayName: 'View',
+          children: [{
+            displayName: 'Foo',
+            children: [{
+              displayName: 'View',
+              children: [],
+            }],
+          }],
+        };
+
+        var elementAfter = <View><Foo><Image /></Foo></View>;
+        var treeAfter = {
+          displayName: 'View',
+          children: [{
+            displayName: 'Foo',
+            children: [{
+              displayName: 'Image',
+              children: [],
+            }],
+          }],
+        };
+
+        assertTreeMatches([
+          [elementBefore, treeBefore],
+          [elementAfter, treeAfter],
+        ]);
+      });
+
+      it('updates from no children to a single composite child', () => {
+        function Foo() {
+          return null;
+        }
+
+        var elementBefore = <View />;
+        var treeBefore = {
+          displayName: 'View',
+          children: [],
+        };
+
+        var elementAfter = <View><Foo /></View>;
+        var treeAfter = {
+          displayName: 'View',
+          children: [{
+            displayName: 'Foo',
+            children: [],
+          }],
+        };
+
+        assertTreeMatches([
+          [elementBefore, treeBefore],
+          [elementAfter, treeAfter],
+        ]);
+      });
+
+      it('updates from a single composite child to no children', () => {
+        function Foo() {
+          return null;
+        }
+
+        var elementBefore = <View><Foo /></View>;
+        var treeBefore = {
+          displayName: 'View',
+          children: [{
+            displayName: 'Foo',
+            children: [],
+          }],
+        };
+
+        var elementAfter = <View />;
+        var treeAfter = {
+          displayName: 'View',
+          children: [],
+        };
+
+        assertTreeMatches([
+          [elementBefore, treeBefore],
+          [elementAfter, treeAfter],
+        ]);
+      });
+
+      it('updates mixed children', () => {
+        function Foo() {
+          return <View />;
+        }
+        var element1 = (
+          <View>
+            <Text>hi</Text>
+            {false}
+            <Text>{42}</Text>
+            {null}
+            <Foo />
+          </View>
+        );
+        var tree1 = {
+          displayName: 'View',
+          children: [{
+            displayName: 'Text',
+            children: [{
+              displayName: 'RCText',
+              children: [{
+                displayName: '#text',
+                text: 'hi',
+              }],
+            }],
+          }, {
+            displayName: 'Text',
+            children: [{
+              displayName: 'RCText',
+              children: [{
+                displayName: '#text',
+                text: '42',
+              }],
+            }],
+          }, {
+            displayName: 'Foo',
+            children: [{
+              displayName: 'View',
+              children: [],
+            }],
+          }],
+        };
+
+        var element2 = (
+          <View>
+            <Foo />
+            {false}
+            <Text>hi</Text>
+            {null}
+          </View>
+        );
+        var tree2 = {
+          displayName: 'View',
+          children: [{
+            displayName: 'Foo',
+            children: [{
+              displayName: 'View',
+              children: [],
+            }],
+          }, {
+            displayName: 'Text',
+            children: [{
+              displayName: 'RCText',
+              children: [{
+                displayName: '#text',
+                text: 'hi',
+              }],
+            }],
+          }],
+        };
+
+        var element3 = (
+          <View>
+            <Foo />
+          </View>
+        );
+        var tree3 = {
+          displayName: 'View',
+          children: [{
+            displayName: 'Foo',
+            children: [{
+              displayName: 'View',
+              children: [],
+            }],
+          }],
+        };
+
+        assertTreeMatches([
+          [element1, tree1],
+          [element2, tree2],
+          [element3, tree3],
+        ]);
+      });
+    });
+
+    describe('functional component', () => {
+      it('updates with a native child', () => {
+        function Foo({ children }) {
+          return children;
+        }
+
+        var elementBefore = <Foo><View /></Foo>;
+        var treeBefore = {
+          displayName: 'Foo',
+          children: [{
+            displayName: 'View',
+            children: [],
+          }],
+        };
+
+        var elementAfter = <Foo><Image /></Foo>;
+        var treeAfter = {
+          displayName: 'Foo',
+          children: [{
+            displayName: 'Image',
+            children: [],
+          }],
+        };
+
+        assertTreeMatches([
+          [elementBefore, treeBefore],
+          [elementAfter, treeAfter],
+        ]);
+      });
+
+      it('updates from null to a native child', () => {
+        function Foo({ children }) {
+          return children;
+        }
+
+        var elementBefore = <Foo>{null}</Foo>;
+        var treeBefore = {
+          displayName: 'Foo',
+          children: [],
+        };
+
+        var elementAfter = <Foo><View /></Foo>;
+        var treeAfter = {
+          displayName: 'Foo',
+          children: [{
+            displayName: 'View',
+            children: [],
+          }],
+        };
+
+        assertTreeMatches([
+          [elementBefore, treeBefore],
+          [elementAfter, treeAfter],
+        ]);
+      });
+
+      it('updates from a native child to null', () => {
+        function Foo({ children }) {
+          return children;
+        }
+
+        var elementBefore = <Foo><View /></Foo>;
+        var treeBefore = {
+          displayName: 'Foo',
+          children: [{
+            displayName: 'View',
+            children: [],
+          }],
+        };
+
+        var elementAfter = <Foo>{null}</Foo>;
+        var treeAfter = {
+          displayName: 'Foo',
+          children: [],
+        };
+
+        assertTreeMatches([
+          [elementBefore, treeBefore],
+          [elementAfter, treeAfter],
+        ]);
+      });
+
+      it('updates from a native child to a composite child', () => {
+        function Bar() {
+          return null;
+        }
+
+        function Foo({ children }) {
+          return children;
+        }
+
+        var elementBefore = <Foo><View /></Foo>;
+        var treeBefore = {
+          displayName: 'Foo',
+          children: [{
+            displayName: 'View',
+            children: [],
+          }],
+        };
+
+        var elementAfter = <Foo><Bar /></Foo>;
+        var treeAfter = {
+          displayName: 'Foo',
+          children: [{
+            displayName: 'Bar',
+            children: [],
+          }],
+        };
+
+        assertTreeMatches([
+          [elementBefore, treeBefore],
+          [elementAfter, treeAfter],
+        ]);
+      });
+
+      it('updates from a composite child to a native child', () => {
+        function Bar() {
+          return null;
+        }
+
+        function Foo({ children }) {
+          return children;
+        }
+
+        var elementBefore = <Foo><Bar /></Foo>;
+        var treeBefore = {
+          displayName: 'Foo',
+          children: [{
+            displayName: 'Bar',
+            children: [],
+          }],
+        };
+
+        var elementAfter = <Foo><View /></Foo>;
+        var treeAfter = {
+          displayName: 'Foo',
+          children: [{
+            displayName: 'View',
+            children: [],
+          }],
+        };
+
+        assertTreeMatches([
+          [elementBefore, treeBefore],
+          [elementAfter, treeAfter],
+        ]);
+      });
+
+      it('updates from null to a composite child', () => {
+        function Bar() {
+          return null;
+        }
+
+        function Foo({ children }) {
+          return children;
+        }
+
+        var elementBefore = <Foo>{null}</Foo>;
+        var treeBefore = {
+          displayName: 'Foo',
+          children: [],
+        };
+
+        var elementAfter = <Foo><Bar /></Foo>;
+        var treeAfter = {
+          displayName: 'Foo',
+          children: [{
+            displayName: 'Bar',
+            children: [],
+          }],
+        };
+
+        assertTreeMatches([
+          [elementBefore, treeBefore],
+          [elementAfter, treeAfter],
+        ]);
+      });
+
+      it('updates from a composite child to null', () => {
+        function Bar() {
+          return null;
+        }
+
+        function Foo({ children }) {
+          return children;
+        }
+
+        var elementBefore = <Foo><Bar /></Foo>;
+        var treeBefore = {
+          displayName: 'Foo',
+          children: [{
+            displayName: 'Bar',
+            children: [],
+          }],
+        };
+
+        var elementAfter = <Foo>{null}</Foo>;
+        var treeAfter = {
+          displayName: 'Foo',
+          children: [],
+        };
+
+        assertTreeMatches([
+          [elementBefore, treeBefore],
+          [elementAfter, treeAfter],
+        ]);
+      });
+    });
+
+    describe('class component', () => {
+      it('updates with a native child', () => {
+        var Foo = React.createClass({
+          render() {
+            return this.props.children;
+          },
+        });
+
+        var elementBefore = <Foo><View /></Foo>;
+        var treeBefore = {
+          displayName: 'Foo',
+          children: [{
+            displayName: 'View',
+            children: [],
+          }],
+        };
+
+        var elementAfter = <Foo><Image /></Foo>;
+        var treeAfter = {
+          displayName: 'Foo',
+          children: [{
+            displayName: 'Image',
+            children: [],
+          }],
+        };
+
+        assertTreeMatches([
+          [elementBefore, treeBefore],
+          [elementAfter, treeAfter],
+        ]);
+      });
+
+      it('updates from null to a native child', () => {
+        var Foo = React.createClass({
+          render() {
+            return this.props.children;
+          },
+        });
+
+        var elementBefore = <Foo>{null}</Foo>;
+        var treeBefore = {
+          displayName: 'Foo',
+          children: [],
+        };
+
+        var elementAfter = <Foo><View /></Foo>;
+        var treeAfter = {
+          displayName: 'Foo',
+          children: [{
+            displayName: 'View',
+            children: [],
+          }],
+        };
+
+        assertTreeMatches([
+          [elementBefore, treeBefore],
+          [elementAfter, treeAfter],
+        ]);
+      });
+
+      it('updates from a native child to null', () => {
+        var Foo = React.createClass({
+          render() {
+            return this.props.children;
+          },
+        });
+
+        var elementBefore = <Foo><View /></Foo>;
+        var treeBefore = {
+          displayName: 'Foo',
+          children: [{
+            displayName: 'View',
+            children: [],
+          }],
+        };
+
+        var elementAfter = <Foo>{null}</Foo>;
+        var treeAfter = {
+          displayName: 'Foo',
+          children: [],
+        };
+
+        assertTreeMatches([
+          [elementBefore, treeBefore],
+          [elementAfter, treeAfter],
+        ]);
+      });
+
+      it('updates from a native child to a composite child', () => {
+        var Bar = React.createClass({
+          render() {
+            return null;
+          },
+        });
+
+        var Foo = React.createClass({
+          render() {
+            return this.props.children;
+          },
+        });
+
+        var elementBefore = <Foo><View /></Foo>;
+        var treeBefore = {
+          displayName: 'Foo',
+          children: [{
+            displayName: 'View',
+            children: [],
+          }],
+        };
+
+        var elementAfter = <Foo><Bar /></Foo>;
+        var treeAfter = {
+          displayName: 'Foo',
+          children: [{
+            displayName: 'Bar',
+            children: [],
+          }],
+        };
+
+        assertTreeMatches([
+          [elementBefore, treeBefore],
+          [elementAfter, treeAfter],
+        ]);
+      });
+
+      it('updates from a composite child to a native child', () => {
+        var Bar = React.createClass({
+          render() {
+            return null;
+          },
+        });
+
+        var Foo = React.createClass({
+          render() {
+            return this.props.children;
+          },
+        });
+
+        var elementBefore = <Foo><Bar /></Foo>;
+        var treeBefore = {
+          displayName: 'Foo',
+          children: [{
+            displayName: 'Bar',
+            children: [],
+          }],
+        };
+
+        var elementAfter = <Foo><View /></Foo>;
+        var treeAfter = {
+          displayName: 'Foo',
+          children: [{
+            displayName: 'View',
+            children: [],
+          }],
+        };
+
+        assertTreeMatches([
+          [elementBefore, treeBefore],
+          [elementAfter, treeAfter],
+        ]);
+      });
+
+      it('updates from null to a composite child', () => {
+        var Bar = React.createClass({
+          render() {
+            return null;
+          },
+        });
+
+        var Foo = React.createClass({
+          render() {
+            return this.props.children;
+          },
+        });
+
+        var elementBefore = <Foo>{null}</Foo>;
+        var treeBefore = {
+          displayName: 'Foo',
+          children: [],
+        };
+
+        var elementAfter = <Foo><Bar /></Foo>;
+        var treeAfter = {
+          displayName: 'Foo',
+          children: [{
+            displayName: 'Bar',
+            children: [],
+          }],
+        };
+
+        assertTreeMatches([
+          [elementBefore, treeBefore],
+          [elementAfter, treeAfter],
+        ]);
+      });
+
+      it('updates from a composite child to null', () => {
+        var Bar = React.createClass({
+          render() {
+            return null;
+          },
+        });
+
+        var Foo = React.createClass({
+          render() {
+            return this.props.children;
+          },
+        });
+
+        var elementBefore = <Foo><Bar /></Foo>;
+        var treeBefore = {
+          displayName: 'Foo',
+          children: [{
+            displayName: 'Bar',
+            children: [],
+          }],
+        };
+
+        var elementAfter = <Foo>{null}</Foo>;
+        var treeAfter = {
+          displayName: 'Foo',
+          children: [],
+        };
+
+        assertTreeMatches([
+          [elementBefore, treeBefore],
+          [elementAfter, treeAfter],
+        ]);
+      });
+    });
+  });
+
+  it('tracks owner correctly', () => {
+    class Foo extends React.Component {
+      render() {
+        return <Bar><Text>Hi.</Text></Bar>;
+      }
+    }
+    function Bar({children}) {
+      return <View>{children}<Text>Mom</Text></View>;
+    }
+
+    // Note that owner is not calculated for text nodes
+    // because they are not created from real elements.
+    var element = <View><Foo /></View>;
+    var tree = {
+      displayName: 'View',
+      children: [{
+        displayName: 'Foo',
+        children: [{
+          displayName: 'Bar',
+          ownerDisplayName: 'Foo',
+          children: [{
+            displayName: 'View',
+            ownerDisplayName: 'Bar',
+            children: [{
+              displayName: 'Text',
+              ownerDisplayName: 'Foo',
+              children: [{
+                displayName: 'RCText',
+                ownerDisplayName: 'Text',
+                children: [{
+                  displayName: '#text',
+                  text: 'Hi.',
+                }],
+              }],
+            }, {
+              displayName: 'Text',
+              ownerDisplayName: 'Bar',
+              children: [{
+                displayName: 'RCText',
+                ownerDisplayName: 'Text',
+                children: [{
+                  displayName: '#text',
+                  text: 'Mom',
+                }],
+              }],
+            }],
+          }],
+        }],
+      }],
+    };
+    assertTreeMatches([element, tree], {includeOwnerDisplayName: true});
+  });
+
+  it('purges unmounted components automatically', () => {
+    var renderBar = true;
+    var fooInstance;
+    var barInstance;
+
+    class Foo extends React.Component {
+      render() {
+        fooInstance = ReactInstanceMap.get(this);
+        return renderBar ? <Bar /> : null;
+      }
+    }
+
+    class Bar extends React.Component {
+      render() {
+        barInstance = ReactInstanceMap.get(this);
+        return null;
+      }
+    }
+
+    ReactNative.render(<Foo />, 1);
+    expect(
+      getTree(barInstance._debugID, {
+        includeParentDisplayName: true,
+        expectedParentID: fooInstance._debugID,
+      })
+    ).toEqual({
+      displayName: 'Bar',
+      parentDisplayName: 'Foo',
+      children: [],
+    });
+
+    renderBar = false;
+    ReactNative.render(<Foo />, 1);
+    expect(
+      getTree(barInstance._debugID, {expectedParentID: null})
+    ).toEqual({
+      displayName: 'Unknown',
+      children: [],
+    });
+
+    ReactNative.unmountComponentAtNode(1);
+    expect(
+      getTree(barInstance._debugID, {expectedParentID: null})
+    ).toEqual({
+      displayName: 'Unknown',
+      children: [],
+    });
+  });
+
+  it('reports update counts', () => {
+    ReactNative.render(<View />, 1);
+    var viewID = ReactComponentTreeDevtool.getRootIDs()[0];
+    expect(ReactComponentTreeDevtool.getUpdateCount(viewID)).toEqual(0);
+
+    ReactNative.render(<Image />, 1);
+    var imageID = ReactComponentTreeDevtool.getRootIDs()[0];
+    expect(ReactComponentTreeDevtool.getUpdateCount(viewID)).toEqual(0);
+    expect(ReactComponentTreeDevtool.getUpdateCount(imageID)).toEqual(0);
+
+    ReactNative.render(<Image />, 1);
+    expect(ReactComponentTreeDevtool.getUpdateCount(viewID)).toEqual(0);
+    expect(ReactComponentTreeDevtool.getUpdateCount(imageID)).toEqual(1);
+
+    ReactNative.render(<Image />, 1);
+    expect(ReactComponentTreeDevtool.getUpdateCount(viewID)).toEqual(0);
+    expect(ReactComponentTreeDevtool.getUpdateCount(imageID)).toEqual(2);
+
+    ReactNative.unmountComponentAtNode(1);
+    expect(ReactComponentTreeDevtool.getUpdateCount(viewID)).toEqual(0);
+    expect(ReactComponentTreeDevtool.getUpdateCount(imageID)).toEqual(0);
+  });
+
+  it('does not report top-level wrapper as a root', () => {
+    ReactNative.render(<View><Image /></View>, 1);
+    expect(getRootDisplayNames()).toEqual(['View']);
+
+    ReactNative.render(<View><Text /></View>, 1);
+    expect(getRootDisplayNames()).toEqual(['View']);
+
+    ReactNative.unmountComponentAtNode(1);
+    expect(getRootDisplayNames()).toEqual([]);
+    expect(getRegisteredDisplayNames()).toEqual([]);
+  });
+});
diff --git a/src/isomorphic/devtools/__tests__/ReactNativeOperationHistoryDevtool-test.js b/src/isomorphic/devtools/__tests__/ReactNativeOperationHistoryDevtool-test.js
new file mode 100644
index 0000000000..769fe675b1
--- /dev/null
+++ b/src/isomorphic/devtools/__tests__/ReactNativeOperationHistoryDevtool-test.js
@@ -0,0 +1,724 @@
+/**
+ * Copyright 2016-present, Facebook, Inc.
+ * All rights reserved.
+ *
+ * This source code is licensed under the BSD-style license found in the
+ * LICENSE file in the root directory of this source tree. An additional grant
+ * of patent rights can be found in the PATENTS file in the same directory.
+ *
+ * @emails react-core
+ */
+
+'use strict';
+
+describe('ReactNativeOperationHistoryDevtool', () => {
+  var React;
+  var ReactDOM;
+  var ReactDOMComponentTree;
+  var ReactDOMFeatureFlags;
+  var ReactNativeOperationHistoryDevtool;
+
+  beforeEach(() => {
+    jest.resetModuleRegistry();
+
+    React = require('React');
+    ReactDOM = require('ReactDOM');
+    ReactDOMComponentTree = require('ReactDOMComponentTree');
+    ReactDOMFeatureFlags = require('ReactDOMFeatureFlags');
+    ReactNativeOperationHistoryDevtool = require('ReactNativeOperationHistoryDevtool');
+  });
+
+  function assertHistoryMatches(expectedHistory) {
+    var actualHistory = ReactNativeOperationHistoryDevtool.getHistory();
+    expect(actualHistory).toEqual(expectedHistory);
+  }
+
+  describe('mount', () => {
+    it('gets recorded for native roots', () => {
+      var node = document.createElement('div');
+      ReactNativeOperationHistoryDevtool._preventClearing = true;
+      ReactDOM.render(<div><p>Hi.</p></div>, node);
+
+      var inst = ReactDOMComponentTree.getInstanceFromNode(node.firstChild);
+      assertHistoryMatches([{
+        instanceID: inst._debugID,
+        type: 'mount',
+        payload: ReactDOMFeatureFlags.useCreateElement ?
+          'DIV' :
+          '<div data-reactroot="" data-reactid="1"><p data-reactid="2">Hi.</p></div>',
+      }]);
+    });
+
+    it('gets recorded for composite roots', () => {
+      function Foo() {
+        return <div><p>Hi.</p></div>;
+      }
+      var node = document.createElement('div');
+
+      ReactNativeOperationHistoryDevtool._preventClearing = true;
+      ReactDOM.render(<Foo />, node);
+
+      var inst = ReactDOMComponentTree.getInstanceFromNode(node.firstChild);
+      assertHistoryMatches([{
+        instanceID: inst._debugID,
+        type: 'mount',
+        payload: ReactDOMFeatureFlags.useCreateElement ?
+          'DIV' :
+          '<div data-reactroot="" data-reactid="1">' +
+          '<p data-reactid="2">Hi.</p></div>',
+      }]);
+    });
+
+    it('gets ignored for composite roots that return null', () => {
+      function Foo() {
+        return null;
+      }
+      var node = document.createElement('div');
+
+      ReactNativeOperationHistoryDevtool._preventClearing = true;
+      ReactDOM.render(<Foo />, node);
+
+      // Empty DOM components should be invisible to devtools.
+      assertHistoryMatches([]);
+    });
+
+    it('gets recorded when a native is mounted deeply instead of null', () => {
+      var element;
+      function Foo() {
+        return element;
+      }
+
+      ReactNativeOperationHistoryDevtool._preventClearing = true;
+
+      var node = document.createElement('div');
+      element = null;
+      ReactDOM.render(<Foo />, node);
+
+      element = <span />;
+      ReactDOM.render(<Foo />, node);
+      var inst = ReactDOMComponentTree.getInstanceFromNode(node.firstChild);
+
+      // Since empty components should be invisible to devtools,
+      // we record a "mount" event rather than a "replace with".
+      assertHistoryMatches([{
+        instanceID: inst._debugID,
+        type: 'mount',
+        payload: 'SPAN',
+      }]);
+    });
+  });
+
+  describe('update styles', () => {
+    it('gets recorded during mount', () => {
+      var node = document.createElement('div');
+
+      ReactNativeOperationHistoryDevtool._preventClearing = true;
+      ReactDOM.render(<div style={{
+        color: 'red',
+        backgroundColor: 'yellow',
+      }} />, node);
+
+      var inst = ReactDOMComponentTree.getInstanceFromNode(node.firstChild);
+      if (ReactDOMFeatureFlags.useCreateElement) {
+        assertHistoryMatches([{
+          instanceID: inst._debugID,
+          type: 'update styles',
+          payload: {
+            color: 'red',
+            backgroundColor: 'yellow',
+          },
+        }, {
+          instanceID: inst._debugID,
+          type: 'mount',
+          payload: 'DIV',
+        }]);
+      } else {
+        assertHistoryMatches([{
+          instanceID: inst._debugID,
+          type: 'mount',
+          payload: '<div style="color:red;background-color:yellow;" ' +
+          'data-reactroot="" data-reactid="1"></div>',
+        }]);
+      }
+    });
+
+    it('gets recorded during an update', () => {
+      var node = document.createElement('div');
+      ReactDOM.render(<div />, node);
+      var inst = ReactDOMComponentTree.getInstanceFromNode(node.firstChild);
+
+      ReactNativeOperationHistoryDevtool._preventClearing = true;
+      ReactDOM.render(<div style={{ color: 'red' }} />, node);
+      ReactDOM.render(<div style={{
+        color: 'blue',
+        backgroundColor: 'yellow',
+      }} />, node);
+      ReactDOM.render(<div style={{ backgroundColor: 'green' }} />, node);
+      ReactDOM.render(<div />, node);
+
+      assertHistoryMatches([{
+        instanceID: inst._debugID,
+        type: 'update styles',
+        payload: { color: 'red' },
+      }, {
+        instanceID: inst._debugID,
+        type: 'update styles',
+        payload: { color: 'blue', backgroundColor: 'yellow' },
+      }, {
+        instanceID: inst._debugID,
+        type: 'update styles',
+        payload: { color: '', backgroundColor: 'green' },
+      }, {
+        instanceID: inst._debugID,
+        type: 'update styles',
+        payload: { backgroundColor: '' },
+      }]);
+    });
+
+    it('gets ignored if the styles are shallowly equal', () => {
+      var node = document.createElement('div');
+      ReactDOM.render(<div />, node);
+      var inst = ReactDOMComponentTree.getInstanceFromNode(node.firstChild);
+
+      ReactNativeOperationHistoryDevtool._preventClearing = true;
+      ReactDOM.render(<div style={{
+        color: 'red',
+        backgroundColor: 'yellow',
+      }} />, node);
+      ReactDOM.render(<div style={{
+        color: 'red',
+        backgroundColor: 'yellow',
+      }} />, node);
+
+      assertHistoryMatches([{
+        instanceID: inst._debugID,
+        type: 'update styles',
+        payload: {
+          color: 'red',
+          backgroundColor: 'yellow',
+        },
+      }]);
+    });
+  });
+
+  describe('update attribute', () => {
+    describe('simple attribute', () => {
+      it('gets recorded during mount', () => {
+        var node = document.createElement('div');
+
+        ReactNativeOperationHistoryDevtool._preventClearing = true;
+        ReactDOM.render(<div className="rad" tabIndex={42} />, node);
+
+        var inst = ReactDOMComponentTree.getInstanceFromNode(node.firstChild);
+        if (ReactDOMFeatureFlags.useCreateElement) {
+          assertHistoryMatches([{
+            instanceID: inst._debugID,
+            type: 'update attribute',
+            payload: { className: 'rad' },
+          }, {
+            instanceID: inst._debugID,
+            type: 'update attribute',
+            payload: { tabIndex: 42 },
+          }, {
+            instanceID: inst._debugID,
+            type: 'mount',
+            payload: 'DIV',
+          }]);
+        } else {
+          assertHistoryMatches([{
+            instanceID: inst._debugID,
+            type: 'mount',
+            payload: '<div class="rad" tabindex="42" data-reactroot="" ' +
+            'data-reactid="1"></div>',
+          }]);
+        }
+      });
+
+      it('gets recorded during an update', () => {
+        var node = document.createElement('div');
+        ReactDOM.render(<div />, node);
+        var inst = ReactDOMComponentTree.getInstanceFromNode(node.firstChild);
+
+        ReactNativeOperationHistoryDevtool._preventClearing = true;
+        ReactDOM.render(<div className="rad" />, node);
+        ReactDOM.render(<div className="mad" tabIndex={42} />, node);
+        ReactDOM.render(<div tabIndex={43} />, node);
+
+        assertHistoryMatches([{
+          instanceID: inst._debugID,
+          type: 'update attribute',
+          payload: { className: 'rad' },
+        }, {
+          instanceID: inst._debugID,
+          type: 'update attribute',
+          payload: { className: 'mad' },
+        }, {
+          instanceID: inst._debugID,
+          type: 'update attribute',
+          payload: { tabIndex: 42 },
+        }, {
+          instanceID: inst._debugID,
+          type: 'remove attribute',
+          payload: 'className',
+        }, {
+          instanceID: inst._debugID,
+          type: 'update attribute',
+          payload: { tabIndex: 43 },
+        }]);
+      });
+    });
+
+    describe('attribute that gets removed with certain values', () => {
+      it('gets recorded as a removal during an update', () => {
+        var node = document.createElement('div');
+        ReactDOM.render(<div />, node);
+        var inst = ReactDOMComponentTree.getInstanceFromNode(node.firstChild);
+
+        ReactNativeOperationHistoryDevtool._preventClearing = true;
+        ReactDOM.render(<div disabled={true} />, node);
+        ReactDOM.render(<div disabled={false} />, node);
+
+        assertHistoryMatches([{
+          instanceID: inst._debugID,
+          type: 'update attribute',
+          payload: { disabled: true },
+        }, {
+          instanceID: inst._debugID,
+          type: 'remove attribute',
+          payload: 'disabled',
+        }]);
+      });
+    });
+
+    describe('custom attribute', () => {
+      it('gets recorded during mount', () => {
+        var node = document.createElement('div');
+
+        ReactNativeOperationHistoryDevtool._preventClearing = true;
+        ReactDOM.render(<div data-x="rad" data-y={42} />, node);
+
+        var inst = ReactDOMComponentTree.getInstanceFromNode(node.firstChild);
+        if (ReactDOMFeatureFlags.useCreateElement) {
+          assertHistoryMatches([{
+            instanceID: inst._debugID,
+            type: 'update attribute',
+            payload: { 'data-x': 'rad' },
+          }, {
+            instanceID: inst._debugID,
+            type: 'update attribute',
+            payload: { 'data-y': 42 },
+          }, {
+            instanceID: inst._debugID,
+            type: 'mount',
+            payload: 'DIV',
+          }]);
+        } else {
+          assertHistoryMatches([{
+            instanceID: inst._debugID,
+            type: 'mount',
+            payload: '<div data-x="rad" data-y="42" data-reactroot="" ' +
+            'data-reactid="1"></div>',
+          }]);
+        }
+      });
+
+      it('gets recorded during an update', () => {
+        var node = document.createElement('div');
+        ReactDOM.render(<div />, node);
+        var inst = ReactDOMComponentTree.getInstanceFromNode(node.firstChild);
+
+        ReactNativeOperationHistoryDevtool._preventClearing = true;
+        ReactDOM.render(<div data-x="rad" />, node);
+        ReactDOM.render(<div data-x="mad" data-y={42} />, node);
+        ReactDOM.render(<div data-y={43} />, node);
+
+        assertHistoryMatches([{
+          instanceID: inst._debugID,
+          type: 'update attribute',
+          payload: { 'data-x': 'rad' },
+        }, {
+          instanceID: inst._debugID,
+          type: 'update attribute',
+          payload: { 'data-x': 'mad' },
+        }, {
+          instanceID: inst._debugID,
+          type: 'update attribute',
+          payload: { 'data-y': 42 },
+        }, {
+          instanceID: inst._debugID,
+          type: 'remove attribute',
+          payload: 'data-x',
+        }, {
+          instanceID: inst._debugID,
+          type: 'update attribute',
+          payload: { 'data-y': 43 },
+        }]);
+      });
+    });
+
+    describe('attribute on a web component', () => {
+      it('gets recorded during mount', () => {
+        var node = document.createElement('div');
+
+        ReactNativeOperationHistoryDevtool._preventClearing = true;
+        ReactDOM.render(<my-component className="rad" tabIndex={42} />, node);
+
+        var inst = ReactDOMComponentTree.getInstanceFromNode(node.firstChild);
+        if (ReactDOMFeatureFlags.useCreateElement) {
+          assertHistoryMatches([{
+            instanceID: inst._debugID,
+            type: 'update attribute',
+            payload: { className: 'rad' },
+          }, {
+            instanceID: inst._debugID,
+            type: 'update attribute',
+            payload: { tabIndex: 42 },
+          }, {
+            instanceID: inst._debugID,
+            type: 'mount',
+            payload: 'MY-COMPONENT',
+          }]);
+        } else {
+          assertHistoryMatches([{
+            instanceID: inst._debugID,
+            type: 'mount',
+            payload: '<my-component className="rad" tabIndex="42" ' +
+            'data-reactroot="" data-reactid="1"></my-component>',
+          }]);
+        }
+      });
+
+      it('gets recorded during an update', () => {
+        var node = document.createElement('div');
+        ReactDOM.render(<my-component />, node);
+        var inst = ReactDOMComponentTree.getInstanceFromNode(node.firstChild);
+
+        ReactNativeOperationHistoryDevtool._preventClearing = true;
+        ReactDOM.render(<my-component className="rad" />, node);
+        ReactDOM.render(<my-component className="mad" tabIndex={42} />, node);
+        ReactDOM.render(<my-component tabIndex={43} />, node);
+
+        assertHistoryMatches([{
+          instanceID: inst._debugID,
+          type: 'update attribute',
+          payload: { className: 'rad' },
+        }, {
+          instanceID: inst._debugID,
+          type: 'update attribute',
+          payload: { className: 'mad' },
+        }, {
+          instanceID: inst._debugID,
+          type: 'update attribute',
+          payload: { tabIndex: 42 },
+        }, {
+          instanceID: inst._debugID,
+          type: 'remove attribute',
+          payload: 'className',
+        }, {
+          instanceID: inst._debugID,
+          type: 'update attribute',
+          payload: { tabIndex: 43 },
+        }]);
+      });
+    });
+  });
+
+  describe('replace text', () => {
+    describe('text content', () => {
+      it('gets recorded during an update from text content', () => {
+        var node = document.createElement('div');
+        ReactDOM.render(<div>Hi.</div>, node);
+        var inst = ReactDOMComponentTree.getInstanceFromNode(node.firstChild);
+
+        ReactNativeOperationHistoryDevtool._preventClearing = true;
+        ReactDOM.render(<div>Bye.</div>, node);
+
+        assertHistoryMatches([{
+          instanceID: inst._debugID,
+          type: 'replace text',
+          payload: 'Bye.',
+        }]);
+      });
+
+      it('gets recorded during an update from html', () => {
+        var node = document.createElement('div');
+        ReactDOM.render(<div dangerouslySetInnerHTML={{__html: 'Hi.'}} />, node);
+        var inst = ReactDOMComponentTree.getInstanceFromNode(node.firstChild);
+
+        ReactNativeOperationHistoryDevtool._preventClearing = true;
+        ReactDOM.render(<div>Bye.</div>, node);
+
+        assertHistoryMatches([{
+          instanceID: inst._debugID,
+          type: 'replace text',
+          payload: 'Bye.',
+        }]);
+      });
+
+      it('gets recorded during an update from children', () => {
+        var node = document.createElement('div');
+        ReactDOM.render(<div><span /><p /></div>, node);
+        var inst = ReactDOMComponentTree.getInstanceFromNode(node.firstChild);
+
+        ReactNativeOperationHistoryDevtool._preventClearing = true;
+        ReactDOM.render(<div>Bye.</div>, node);
+
+        assertHistoryMatches([{
+          instanceID: inst._debugID,
+          type: 'remove child',
+          payload: {fromIndex: 0},
+        }, {
+          instanceID: inst._debugID,
+          type: 'remove child',
+          payload: {fromIndex: 1},
+        }, {
+          instanceID: inst._debugID,
+          type: 'replace text',
+          payload: 'Bye.',
+        }]);
+      });
+
+      it('gets ignored if new text is equal', () => {
+        var node = document.createElement('div');
+        ReactDOM.render(<div>Hi.</div>, node);
+
+        ReactNativeOperationHistoryDevtool._preventClearing = true;
+        ReactDOM.render(<div>Hi.</div>, node);
+
+        assertHistoryMatches([]);
+      });
+    });
+
+    describe('text node', () => {
+      it('gets recorded during an update', () => {
+        var node = document.createElement('div');
+        ReactDOM.render(<div>{'Hi.'}{42}</div>, node);
+        var inst1 = ReactDOMComponentTree.getInstanceFromNode(node.firstChild.childNodes[0]);
+        var inst2 = ReactDOMComponentTree.getInstanceFromNode(node.firstChild.childNodes[3]);
+
+        ReactNativeOperationHistoryDevtool._preventClearing = true;
+        ReactDOM.render(<div>{'Bye.'}{43}</div>, node);
+
+        assertHistoryMatches([{
+          instanceID: inst1._debugID,
+          type: 'replace text',
+          payload: 'Bye.',
+        }, {
+          instanceID: inst2._debugID,
+          type: 'replace text',
+          payload: '43',
+        }]);
+      });
+
+      it('gets ignored if new text is equal', () => {
+        var node = document.createElement('div');
+        ReactDOM.render(<div>{'Hi.'}{42}</div>, node);
+
+        ReactNativeOperationHistoryDevtool._preventClearing = true;
+        ReactDOM.render(<div>{'Hi.'}{42}</div>, node);
+
+        assertHistoryMatches([]);
+      });
+    });
+  });
+
+  describe('replace with', () => {
+    it('gets recorded when composite renders to a different type', () => {
+      var element;
+      function Foo() {
+        return element;
+      }
+
+      var node = document.createElement('div');
+      element = <div />;
+      ReactDOM.render(<Foo />, node);
+      var inst = ReactDOMComponentTree.getInstanceFromNode(node.firstChild);
+
+      element = <span />;
+
+      ReactNativeOperationHistoryDevtool._preventClearing = true;
+      ReactDOM.render(<Foo />, node);
+
+      assertHistoryMatches([{
+        instanceID: inst._debugID,
+        type: 'replace with',
+        payload: 'SPAN',
+      }]);
+    });
+
+    it('gets recorded when composite renders to null after a native', () => {
+      var element;
+      function Foo() {
+        return element;
+      }
+
+      var node = document.createElement('div');
+      element = <span />;
+      ReactDOM.render(<Foo />, node);
+
+      var inst = ReactDOMComponentTree.getInstanceFromNode(node.firstChild);
+      element = null;
+
+      ReactNativeOperationHistoryDevtool._preventClearing = true;
+      ReactDOM.render(<Foo />, node);
+
+      assertHistoryMatches([{
+        instanceID: inst._debugID,
+        type: 'replace with',
+        payload: '#comment',
+      }]);
+    });
+
+    it('gets ignored if the type has not changed', () => {
+      var element;
+      function Foo() {
+        return element;
+      }
+
+      var node = document.createElement('div');
+      element = <div />;
+      ReactDOM.render(<Foo />, node);
+
+      element = <div />;
+
+      ReactNativeOperationHistoryDevtool._preventClearing = true;
+      ReactDOM.render(<Foo />, node);
+
+      assertHistoryMatches([]);
+    });
+  });
+
+  describe('replace children', () => {
+    it('gets recorded during an update from text content', () => {
+      var node = document.createElement('div');
+      ReactDOM.render(<div>Hi.</div>, node);
+      var inst = ReactDOMComponentTree.getInstanceFromNode(node.firstChild);
+
+      ReactNativeOperationHistoryDevtool._preventClearing = true;
+      ReactDOM.render(
+        <div dangerouslySetInnerHTML={{__html: 'Bye.'}} />,
+        node
+      );
+
+      assertHistoryMatches([{
+        instanceID: inst._debugID,
+        type: 'replace children',
+        payload: 'Bye.',
+      }]);
+    });
+
+    it('gets recorded during an update from html', () => {
+      var node = document.createElement('div');
+      ReactDOM.render(
+        <div dangerouslySetInnerHTML={{__html: 'Hi.'}} />,
+        node
+      );
+      var inst = ReactDOMComponentTree.getInstanceFromNode(node.firstChild);
+
+      ReactNativeOperationHistoryDevtool._preventClearing = true;
+      ReactDOM.render(
+        <div dangerouslySetInnerHTML={{__html: 'Bye.'}} />,
+        node
+      );
+
+      assertHistoryMatches([{
+        instanceID: inst._debugID,
+        type: 'replace children',
+        payload: 'Bye.',
+      }]);
+    });
+
+    it('gets recorded during an update from children', () => {
+      var node = document.createElement('div');
+      ReactDOM.render(<div><span /><p /></div>, node);
+      var inst = ReactDOMComponentTree.getInstanceFromNode(node.firstChild);
+
+      ReactNativeOperationHistoryDevtool._preventClearing = true;
+      ReactDOM.render(
+        <div dangerouslySetInnerHTML={{__html: 'Hi.'}} />,
+        node
+      );
+
+      assertHistoryMatches([{
+        instanceID: inst._debugID,
+        type: 'remove child',
+        payload: {fromIndex: 0},
+      }, {
+        instanceID: inst._debugID,
+        type: 'remove child',
+        payload: {fromIndex: 1},
+      }, {
+        instanceID: inst._debugID,
+        type: 'replace children',
+        payload: 'Hi.',
+      }]);
+    });
+
+    it('gets ignored if new html is equal', () => {
+      var node = document.createElement('div');
+      ReactDOM.render(
+        <div dangerouslySetInnerHTML={{__html: 'Hi.'}} />,
+        node
+      );
+
+      ReactNativeOperationHistoryDevtool._preventClearing = true;
+      ReactDOM.render(
+        <div dangerouslySetInnerHTML={{__html: 'Hi.'}} />,
+        node
+      );
+
+      assertHistoryMatches([]);
+    });
+  });
+
+  describe('insert child', () => {
+    it('gets reported when a child is inserted', () => {
+      var node = document.createElement('div');
+      ReactDOM.render(<div><span /></div>, node);
+      var inst = ReactDOMComponentTree.getInstanceFromNode(node.firstChild);
+
+      ReactNativeOperationHistoryDevtool._preventClearing = true;
+      ReactDOM.render(<div><span /><p /></div>, node);
+
+      assertHistoryMatches([{
+        instanceID: inst._debugID,
+        type: 'insert child',
+        payload: {toIndex: 1, content: 'P'},
+      }]);
+    });
+  });
+
+  describe('move child', () => {
+    it('gets reported when a child is inserted', () => {
+      var node = document.createElement('div');
+      ReactDOM.render(<div><span key="a" /><p key="b" /></div>, node);
+      var inst = ReactDOMComponentTree.getInstanceFromNode(node.firstChild);
+
+      ReactNativeOperationHistoryDevtool._preventClearing = true;
+      ReactDOM.render(<div><p key="b" /><span key="a" /></div>, node);
+
+      assertHistoryMatches([{
+        instanceID: inst._debugID,
+        type: 'move child',
+        payload: {fromIndex: 0, toIndex: 1},
+      }]);
+    });
+  });
+
+  describe('remove child', () => {
+    it('gets reported when a child is removed', () => {
+      var node = document.createElement('div');
+      ReactDOM.render(<div><span key="a" /><p key="b" /></div>, node);
+      var inst = ReactDOMComponentTree.getInstanceFromNode(node.firstChild);
+
+      ReactNativeOperationHistoryDevtool._preventClearing = true;
+      ReactDOM.render(<div><span key="a" /></div>, node);
+
+      assertHistoryMatches([{
+        instanceID: inst._debugID,
+        type: 'remove child',
+        payload: {fromIndex: 1},
+      }]);
+    });
+  });
+});
diff --git a/src/renderers/dom/ReactDOM.js b/src/renderers/dom/ReactDOM.js
index 75644b1209..7e7fbe4639 100644
--- a/src/renderers/dom/ReactDOM.js
+++ b/src/renderers/dom/ReactDOM.js
@@ -16,7 +16,6 @@
 var ReactDOMComponentTree = require('ReactDOMComponentTree');
 var ReactDefaultInjection = require('ReactDefaultInjection');
 var ReactMount = require('ReactMount');
-var ReactPerf = require('ReactPerf');
 var ReactReconciler = require('ReactReconciler');
 var ReactUpdates = require('ReactUpdates');
 var ReactVersion = require('ReactVersion');
@@ -28,11 +27,9 @@ var warning = require('warning');
 
 ReactDefaultInjection.inject();
 
-var render = ReactPerf.measure('React', 'render', ReactMount.render);
-
 var React = {
   findDOMNode: findDOMNode,
-  render: render,
+  render: ReactMount.render,
   unmountComponentAtNode: ReactMount.unmountComponentAtNode,
   version: ReactVersion,
 
diff --git a/src/renderers/dom/client/ReactDOMIDOperations.js b/src/renderers/dom/client/ReactDOMIDOperations.js
index cb03d3f06a..fd8c16797b 100644
--- a/src/renderers/dom/client/ReactDOMIDOperations.js
+++ b/src/renderers/dom/client/ReactDOMIDOperations.js
@@ -13,7 +13,6 @@
 
 var DOMChildrenOperations = require('DOMChildrenOperations');
 var ReactDOMComponentTree = require('ReactDOMComponentTree');
-var ReactPerf = require('ReactPerf');
 
 /**
  * Operations used to process updates to DOM nodes.
@@ -32,8 +31,4 @@ var ReactDOMIDOperations = {
   },
 };
 
-ReactPerf.measureMethods(ReactDOMIDOperations, 'ReactDOMIDOperations', {
-  dangerouslyProcessChildrenUpdates: 'dangerouslyProcessChildrenUpdates',
-});
-
 module.exports = ReactDOMIDOperations;
diff --git a/src/renderers/dom/client/ReactMount.js b/src/renderers/dom/client/ReactMount.js
index 7f6f8cac6f..6ec60a21fa 100644
--- a/src/renderers/dom/client/ReactMount.js
+++ b/src/renderers/dom/client/ReactMount.js
@@ -22,7 +22,6 @@ var ReactElement = require('ReactElement');
 var ReactFeatureFlags = require('ReactFeatureFlags');
 var ReactInstrumentation = require('ReactInstrumentation');
 var ReactMarkupChecksum = require('ReactMarkupChecksum');
-var ReactPerf = require('ReactPerf');
 var ReactReconciler = require('ReactReconciler');
 var ReactUpdateQueue = require('ReactUpdateQueue');
 var ReactUpdates = require('ReactUpdates');
@@ -308,6 +307,10 @@ var ReactMount = {
     shouldReuseMarkup,
     context
   ) {
+    if (__DEV__) {
+      ReactInstrumentation.debugTool.onBeginFlush();
+    }
+
     // Various parts of our code (such as ReactCompositeComponent's
     // _renderValidatedComponent) assume that calls to render aren't nested;
     // verify that that's the case.
@@ -333,6 +336,12 @@ var ReactMount = {
     ReactBrowserEventEmitter.ensureScrollValueMonitoring();
     var componentInstance = instantiateReactComponent(nextElement);
 
+    if (__DEV__) {
+      // Mute future events from the top level wrapper.
+      // It is an implementation detail that devtools should not know about.
+      componentInstance._debugID = 0;
+    }
+
     // The initial render is synchronous but any updates that happen during
     // rendering, in componentWillMount or componentDidMount, will be batched
     // according to the current batching strategy.
@@ -349,7 +358,11 @@ var ReactMount = {
     instancesByReactRootID[wrapperID] = componentInstance;
 
     if (__DEV__) {
-      ReactInstrumentation.debugTool.onMountRootComponent(componentInstance);
+      // The instance here is TopLevelWrapper so we report mount for its child.
+      ReactInstrumentation.debugTool.onMountRootComponent(
+        componentInstance._renderedComponent._debugID
+      );
+      ReactInstrumentation.debugTool.onEndFlush();
     }
 
     return componentInstance;
@@ -497,6 +510,7 @@ var ReactMount = {
 
   /**
    * Renders a React component into the DOM in the supplied `container`.
+   * See https://facebook.github.io/react/docs/top-level-api.html#reactdom.render
    *
    * If the React component was previously rendered into `container`, this will
    * perform an update on it and only mutate the DOM as necessary to reflect the
@@ -513,6 +527,7 @@ var ReactMount = {
 
   /**
    * Unmounts and destroys the React component rendered in the `container`.
+   * See https://facebook.github.io/react/docs/top-level-api.html#reactdom.unmountcomponentatnode
    *
    * @param {DOMElement} container DOM element containing a React component.
    * @return {boolean} True if a component was found in and unmounted from
@@ -684,12 +699,18 @@ var ReactMount = {
       setInnerHTML(container, markup);
       ReactDOMComponentTree.precacheNode(instance, container.firstChild);
     }
+
+    if (__DEV__) {
+      var nativeNode = ReactDOMComponentTree.getInstanceFromNode(container.firstChild);
+      if (nativeNode._debugID !== 0) {
+        ReactInstrumentation.debugTool.onNativeOperation(
+          nativeNode._debugID,
+          'mount',
+          markup.toString()
+        );
+      }
+    }
   },
 };
 
-ReactPerf.measureMethods(ReactMount, 'ReactMount', {
-  _renderNewRootComponent: '_renderNewRootComponent',
-  _mountImageIntoNode: '_mountImageIntoNode',
-});
-
 module.exports = ReactMount;
diff --git a/src/renderers/dom/client/__tests__/ReactBrowserEventEmitter-test.js b/src/renderers/dom/client/__tests__/ReactBrowserEventEmitter-test.js
index 5dbf91c2cd..9de6b2e8e2 100644
--- a/src/renderers/dom/client/__tests__/ReactBrowserEventEmitter-test.js
+++ b/src/renderers/dom/client/__tests__/ReactBrowserEventEmitter-test.js
@@ -35,7 +35,7 @@ var recordIDAndReturnFalse = function(id, event) {
   recordID(id);
   return false;
 };
-var LISTENER = jest.genMockFn();
+var LISTENER = jest.fn();
 var ON_CLICK_KEY = keyOf({onClick: null});
 var ON_TOUCH_TAP_KEY = keyOf({onTouchTap: null});
 var ON_CHANGE_KEY = keyOf({onChange: null});
@@ -284,7 +284,7 @@ describe('ReactBrowserEventEmitter', function() {
    */
 
   it('should invoke handlers that were removed while bubbling', function() {
-    var handleParentClick = jest.genMockFn();
+    var handleParentClick = jest.fn();
     var handleChildClick = function(event) {
       EventPluginHub.deleteAllListeners(getInternal(PARENT));
     };
@@ -303,7 +303,7 @@ describe('ReactBrowserEventEmitter', function() {
   });
 
   it('should not invoke newly inserted handlers while bubbling', function() {
-    var handleParentClick = jest.genMockFn();
+    var handleParentClick = jest.fn();
     var handleChildClick = function(event) {
       EventPluginHub.putListener(
         getInternal(PARENT),
diff --git a/src/renderers/dom/client/__tests__/ReactDOMIDOperations-test.js b/src/renderers/dom/client/__tests__/ReactDOMIDOperations-test.js
index bdeb485e24..431a21e0f2 100644
--- a/src/renderers/dom/client/__tests__/ReactDOMIDOperations-test.js
+++ b/src/renderers/dom/client/__tests__/ReactDOMIDOperations-test.js
@@ -12,15 +12,18 @@
 'use strict';
 
 describe('ReactDOMIDOperations', function() {
+  var ReactDOMComponentTree = require('ReactDOMComponentTree');
   var ReactDOMIDOperations = require('ReactDOMIDOperations');
   var ReactMultiChildUpdateTypes = require('ReactMultiChildUpdateTypes');
 
   it('should update innerHTML and preserve whitespace', function() {
     var stubNode = document.createElement('div');
-    var html = '\n  \t  <span>  \n  testContent  \t  </span>  \n  \t';
+    var stubInstance = {_debugID: 1};
+    ReactDOMComponentTree.precacheNode(stubInstance, stubNode);
 
+    var html = '\n  \t  <span>  \n  testContent  \t  </span>  \n  \t';
     ReactDOMIDOperations.dangerouslyProcessChildrenUpdates(
-      {_nativeNode: stubNode},
+      stubInstance,
       [{
         type: ReactMultiChildUpdateTypes.SET_MARKUP,
         content: html,
diff --git a/src/renderers/dom/client/__tests__/ReactEventListener-test.js b/src/renderers/dom/client/__tests__/ReactEventListener-test.js
index 49d4f195d5..049284f8f7 100644
--- a/src/renderers/dom/client/__tests__/ReactEventListener-test.js
+++ b/src/renderers/dom/client/__tests__/ReactEventListener-test.js
@@ -30,7 +30,7 @@ describe('ReactEventListener', function() {
     ReactEventListener = require('ReactEventListener');
     ReactTestUtils = require('ReactTestUtils');
 
-    handleTopLevel = jest.genMockFn();
+    handleTopLevel = jest.fn();
     ReactEventListener._handleTopLevel = handleTopLevel;
   });
 
diff --git a/src/renderers/dom/client/__tests__/ReactMount-test.js b/src/renderers/dom/client/__tests__/ReactMount-test.js
index 06b1c16415..96ca4aef33 100644
--- a/src/renderers/dom/client/__tests__/ReactMount-test.js
+++ b/src/renderers/dom/client/__tests__/ReactMount-test.js
@@ -87,8 +87,8 @@ describe('ReactMount', function() {
   it('should unmount and remount if the key changes', function() {
     var container = document.createElement('container');
 
-    var mockMount = jest.genMockFn();
-    var mockUnmount = jest.genMockFn();
+    var mockMount = jest.fn();
+    var mockUnmount = jest.fn();
 
     var Component = React.createClass({
       componentDidMount: mockMount,
diff --git a/src/renderers/dom/client/eventPlugins/__tests__/SelectEventPlugin-test.js b/src/renderers/dom/client/eventPlugins/__tests__/SelectEventPlugin-test.js
index 0f032902d4..46e21b96ce 100644
--- a/src/renderers/dom/client/eventPlugins/__tests__/SelectEventPlugin-test.js
+++ b/src/renderers/dom/client/eventPlugins/__tests__/SelectEventPlugin-test.js
@@ -66,7 +66,7 @@ describe('SelectEventPlugin', function() {
       },
     });
 
-    var cb = jest.genMockFn();
+    var cb = jest.fn();
 
     var rendered = ReactTestUtils.renderIntoDocument(
       <WithSelect onSelect={cb} />
diff --git a/src/renderers/dom/client/findDOMNode.js b/src/renderers/dom/client/findDOMNode.js
index 65c8070093..9c2a3b9ea5 100644
--- a/src/renderers/dom/client/findDOMNode.js
+++ b/src/renderers/dom/client/findDOMNode.js
@@ -22,6 +22,8 @@ var warning = require('warning');
 /**
  * Returns the DOM node rendered by this element.
  *
+ * See https://facebook.github.io/react/docs/top-level-api.html#reactdom.finddomnode
+ *
  * @param {ReactComponent|DOMElement} componentOrElement
  * @return {?DOMElement} The root node of this element.
  */
diff --git a/src/renderers/dom/client/utils/DOMChildrenOperations.js b/src/renderers/dom/client/utils/DOMChildrenOperations.js
index f123aef6ba..4f0da4b7cc 100644
--- a/src/renderers/dom/client/utils/DOMChildrenOperations.js
+++ b/src/renderers/dom/client/utils/DOMChildrenOperations.js
@@ -14,7 +14,8 @@
 var DOMLazyTree = require('DOMLazyTree');
 var Danger = require('Danger');
 var ReactMultiChildUpdateTypes = require('ReactMultiChildUpdateTypes');
-var ReactPerf = require('ReactPerf');
+var ReactDOMComponentTree = require('ReactDOMComponentTree');
+var ReactInstrumentation = require('ReactInstrumentation');
 
 var createMicrosoftUnsafeLocalFunction = require('createMicrosoftUnsafeLocalFunction');
 var setInnerHTML = require('setInnerHTML');
@@ -120,6 +121,37 @@ function replaceDelimitedText(openingComment, closingComment, stringText) {
       removeDelimitedText(parentNode, openingComment, closingComment);
     }
   }
+
+  if (__DEV__) {
+    ReactInstrumentation.debugTool.onNativeOperation(
+      ReactDOMComponentTree.getInstanceFromNode(openingComment)._debugID,
+      'replace text',
+      stringText
+    );
+  }
+}
+
+var dangerouslyReplaceNodeWithMarkup = Danger.dangerouslyReplaceNodeWithMarkup;
+if (__DEV__) {
+  dangerouslyReplaceNodeWithMarkup = function(oldChild, markup, prevInstance) {
+    Danger.dangerouslyReplaceNodeWithMarkup(oldChild, markup);
+    if (prevInstance._debugID !== 0) {
+      ReactInstrumentation.debugTool.onNativeOperation(
+        prevInstance._debugID,
+        'replace with',
+        markup.toString()
+      );
+    } else {
+      var nextInstance = ReactDOMComponentTree.getInstanceFromNode(markup.node);
+      if (nextInstance._debugID !== 0) {
+        ReactInstrumentation.debugTool.onNativeOperation(
+          nextInstance._debugID,
+          'mount',
+          markup.toString()
+        );
+      }
+    }
+  };
 }
 
 /**
@@ -127,7 +159,7 @@ function replaceDelimitedText(openingComment, closingComment, stringText) {
  */
 var DOMChildrenOperations = {
 
-  dangerouslyReplaceNodeWithMarkup: Danger.dangerouslyReplaceNodeWithMarkup,
+  dangerouslyReplaceNodeWithMarkup: dangerouslyReplaceNodeWithMarkup,
 
   replaceDelimitedText: replaceDelimitedText,
 
@@ -139,6 +171,11 @@ var DOMChildrenOperations = {
    * @internal
    */
   processUpdates: function(parentNode, updates) {
+    if (__DEV__) {
+      var parentNodeDebugID =
+        ReactDOMComponentTree.getInstanceFromNode(parentNode)._debugID;
+    }
+
     for (var k = 0; k < updates.length; k++) {
       var update = updates[k];
       switch (update.type) {
@@ -148,6 +185,13 @@ var DOMChildrenOperations = {
             update.content,
             getNodeAfter(parentNode, update.afterNode)
           );
+          if (__DEV__) {
+            ReactInstrumentation.debugTool.onNativeOperation(
+              parentNodeDebugID,
+              'insert child',
+              {toIndex: update.toIndex, content: update.content.toString()}
+            );
+          }
           break;
         case ReactMultiChildUpdateTypes.MOVE_EXISTING:
           moveChild(
@@ -155,21 +199,49 @@ var DOMChildrenOperations = {
             update.fromNode,
             getNodeAfter(parentNode, update.afterNode)
           );
+          if (__DEV__) {
+            ReactInstrumentation.debugTool.onNativeOperation(
+              parentNodeDebugID,
+              'move child',
+              {fromIndex: update.fromIndex, toIndex: update.toIndex}
+            );
+          }
           break;
         case ReactMultiChildUpdateTypes.SET_MARKUP:
           setInnerHTML(
             parentNode,
             update.content
           );
+          if (__DEV__) {
+            ReactInstrumentation.debugTool.onNativeOperation(
+              parentNodeDebugID,
+              'replace children',
+              update.content.toString()
+            );
+          }
           break;
         case ReactMultiChildUpdateTypes.TEXT_CONTENT:
           setTextContent(
             parentNode,
             update.content
           );
+          if (__DEV__) {
+            ReactInstrumentation.debugTool.onNativeOperation(
+              parentNodeDebugID,
+              'replace text',
+              update.content.toString()
+            );
+          }
           break;
         case ReactMultiChildUpdateTypes.REMOVE_NODE:
           removeChild(parentNode, update.fromNode);
+          if (__DEV__) {
+            ReactInstrumentation.debugTool.onNativeOperation(
+              parentNodeDebugID,
+              'remove child',
+              {fromIndex: update.fromIndex}
+            );
+          }
           break;
       }
     }
@@ -177,8 +249,4 @@ var DOMChildrenOperations = {
 
 };
 
-ReactPerf.measureMethods(DOMChildrenOperations, 'DOMChildrenOperations', {
-  replaceDelimitedText: 'replaceDelimitedText',
-});
-
 module.exports = DOMChildrenOperations;
diff --git a/src/renderers/dom/client/utils/DOMLazyTree.js b/src/renderers/dom/client/utils/DOMLazyTree.js
index 249eb475c5..269f5c3714 100644
--- a/src/renderers/dom/client/utils/DOMLazyTree.js
+++ b/src/renderers/dom/client/utils/DOMLazyTree.js
@@ -11,9 +11,14 @@
 
 'use strict';
 
+var DOMNamespaces = require('DOMNamespaces');
+
 var createMicrosoftUnsafeLocalFunction = require('createMicrosoftUnsafeLocalFunction');
 var setTextContent = require('setTextContent');
 
+var ELEMENT_NODE_TYPE = 1;
+var DOCUMENT_FRAGMENT_NODE_TYPE = 11;
+
 /**
  * In IE (8-11) and Edge, appending nodes with no children is dramatically
  * faster than appending a full subtree, so we essentially queue up the
@@ -56,8 +61,15 @@ var insertTreeBefore = createMicrosoftUnsafeLocalFunction(
     // DocumentFragments aren't actually part of the DOM after insertion so
     // appending children won't update the DOM. We need to ensure the fragment
     // is properly populated first, breaking out of our lazy approach for just
-    // this level.
-    if (tree.node.nodeType === 11) {
+    // this level. Also, some <object> plugins (like Flash Player) will read
+    // <param> nodes immediately upon insertion into the DOM, so <object>
+    // must also be populated prior to insertion into the DOM.
+    if (tree.node.nodeType === DOCUMENT_FRAGMENT_NODE_TYPE
+        ||
+        tree.node.nodeType === ELEMENT_NODE_TYPE &&
+        tree.node.nodeName.toLowerCase() === 'object' &&
+        (tree.node.namespaceURI == null ||
+         tree.node.namespaceURI === DOMNamespaces.html)) {
       insertTreeChildren(tree);
       parentNode.insertBefore(tree.node, referenceNode);
     } else {
@@ -96,12 +108,17 @@ function queueText(tree, text) {
   }
 }
 
+function toString() {
+  return this.node.nodeName;
+}
+
 function DOMLazyTree(node) {
   return {
     node: node,
     children: [],
     html: null,
     text: null,
+    toString,
   };
 }
 
diff --git a/src/renderers/dom/client/wrappers/ReactDOMInput.js b/src/renderers/dom/client/wrappers/ReactDOMInput.js
index c1ad1a6330..d4ce97698e 100644
--- a/src/renderers/dom/client/wrappers/ReactDOMInput.js
+++ b/src/renderers/dom/client/wrappers/ReactDOMInput.js
@@ -92,6 +92,8 @@ var ReactDOMInput = {
         inst._currentElement._owner
       );
 
+      var owner = inst._currentElement._owner;
+
       if (props.valueLink !== undefined && !didWarnValueLink) {
         warning(
           false,
@@ -113,11 +115,14 @@ var ReactDOMInput = {
       ) {
         warning(
           false,
+          '%s contains an input of type %s with both checked and defaultChecked props. ' +
           'Input elements must be either controlled or uncontrolled ' +
           '(specify either the checked prop, or the defaultChecked prop, but not ' +
           'both). Decide between using a controlled or uncontrolled input ' +
           'element and remove one of these props. More info: ' +
-          'https://fb.me/react-controlled-components'
+          'https://fb.me/react-controlled-components',
+          owner && owner.getName() || 'A component',
+          props.type
         );
         didWarnCheckedDefaultChecked = true;
       }
@@ -128,11 +133,14 @@ var ReactDOMInput = {
       ) {
         warning(
           false,
+          '%s contains an input of type %s with both value and defaultValue props. ' +
           'Input elements must be either controlled or uncontrolled ' +
           '(specify either the value prop, or the defaultValue prop, but not ' +
           'both). Decide between using a controlled or uncontrolled input ' +
           'element and remove one of these props. More info: ' +
-          'https://fb.me/react-controlled-components'
+          'https://fb.me/react-controlled-components',
+          owner && owner.getName() || 'A component',
+          props.type
         );
         didWarnValueDefaultValue = true;
       }
@@ -169,7 +177,7 @@ var ReactDOMInput = {
       ) {
         warning(
           false,
-          '%s is changing a uncontrolled input of type %s to be controlled. ' +
+          '%s is changing an uncontrolled input of type %s to be controlled. ' +
           'Input elements should not switch from uncontrolled to controlled (or vice versa). ' +
           'Decide between using a controlled or uncontrolled input ' +
           'element for the lifetime of the component. More info: https://fb.me/react-controlled-components',
diff --git a/src/renderers/dom/client/wrappers/__tests__/DisabledInputUtil-test.js b/src/renderers/dom/client/wrappers/__tests__/DisabledInputUtil-test.js
index 0e4c77d556..a99546ecc2 100644
--- a/src/renderers/dom/client/wrappers/__tests__/DisabledInputUtil-test.js
+++ b/src/renderers/dom/client/wrappers/__tests__/DisabledInputUtil-test.js
@@ -36,7 +36,7 @@ describe('DisabledInputUtils', function() {
     return element;
   }
 
-  var onClick = jest.genMockFn();
+  var onClick = jest.fn();
 
   elements.forEach(function(tagName) {
 
diff --git a/src/renderers/dom/client/wrappers/__tests__/ReactDOMInput-test.js b/src/renderers/dom/client/wrappers/__tests__/ReactDOMInput-test.js
index 7a1f57dd0d..a1ab23d9e8 100644
--- a/src/renderers/dom/client/wrappers/__tests__/ReactDOMInput-test.js
+++ b/src/renderers/dom/client/wrappers/__tests__/ReactDOMInput-test.js
@@ -236,7 +236,7 @@ describe('ReactDOMInput', function() {
   });
 
   it('should support ReactLink', function() {
-    var link = new ReactLink('yolo', jest.genMockFn());
+    var link = new ReactLink('yolo', jest.fn());
     var instance = <input type="text" valueLink={link} />;
 
     instance = ReactTestUtils.renderIntoDocument(instance);
@@ -253,7 +253,7 @@ describe('ReactDOMInput', function() {
   });
 
   it('should warn with value and no onChange handler', function() {
-    var link = new ReactLink('yolo', jest.genMockFn());
+    var link = new ReactLink('yolo', jest.fn());
     ReactTestUtils.renderIntoDocument(<input type="text" valueLink={link} />);
     expect(console.error.argsForCall.length).toBe(1);
     expect(console.error.argsForCall[0][0]).toContain(
@@ -261,7 +261,7 @@ describe('ReactDOMInput', function() {
     );
 
     ReactTestUtils.renderIntoDocument(
-      <input type="text" value="zoink" onChange={jest.genMockFn()} />
+      <input type="text" value="zoink" onChange={jest.fn()} />
     );
     expect(console.error.argsForCall.length).toBe(1);
     ReactTestUtils.renderIntoDocument(<input type="text" value="zoink" />);
@@ -293,7 +293,7 @@ describe('ReactDOMInput', function() {
 
   it('should throw if both value and valueLink are provided', function() {
     var node = document.createElement('div');
-    var link = new ReactLink('yolo', jest.genMockFn());
+    var link = new ReactLink('yolo', jest.fn());
     var instance = <input type="text" valueLink={link} />;
 
     expect(() => ReactDOM.render(instance, node)).not.toThrow();
@@ -313,7 +313,7 @@ describe('ReactDOMInput', function() {
   });
 
   it('should support checkedLink', function() {
-    var link = new ReactLink(true, jest.genMockFn());
+    var link = new ReactLink(true, jest.fn());
     var instance = <input type="checkbox" checkedLink={link} />;
 
     instance = ReactTestUtils.renderIntoDocument(instance);
@@ -331,7 +331,7 @@ describe('ReactDOMInput', function() {
 
   it('should warn with checked and no onChange handler', function() {
     var node = document.createElement('div');
-    var link = new ReactLink(true, jest.genMockFn());
+    var link = new ReactLink(true, jest.fn());
     ReactDOM.render(<input type="checkbox" checkedLink={link} />, node);
     expect(console.error.argsForCall.length).toBe(1);
     expect(console.error.argsForCall[0][0]).toContain(
@@ -342,7 +342,7 @@ describe('ReactDOMInput', function() {
       <input
         type="checkbox"
         checked="false"
-        onChange={jest.genMockFn()}
+        onChange={jest.fn()}
       />
     );
     expect(console.error.argsForCall.length).toBe(1);
@@ -370,7 +370,7 @@ describe('ReactDOMInput', function() {
 
   it('should throw if both checked and checkedLink are provided', function() {
     var node = document.createElement('div');
-    var link = new ReactLink(true, jest.genMockFn());
+    var link = new ReactLink(true, jest.fn());
     var instance = <input type="checkbox" checkedLink={link} />;
 
     expect(() => ReactDOM.render(instance, node)).not.toThrow();
@@ -392,7 +392,7 @@ describe('ReactDOMInput', function() {
 
   it('should throw if both checkedLink and valueLink are provided', function() {
     var node = document.createElement('div');
-    var link = new ReactLink(true, jest.genMockFn());
+    var link = new ReactLink(true, jest.fn());
     var instance = <input type="checkbox" checkedLink={link} />;
 
     expect(() => ReactDOM.render(instance, node)).not.toThrow();
@@ -422,6 +422,7 @@ describe('ReactDOMInput', function() {
       <input type="radio" checked={true} defaultChecked={true} readOnly={true} />
     );
     expect(console.error.argsForCall[0][0]).toContain(
+      'A component contains an input of type radio with both checked and defaultChecked props. ' +
       'Input elements must be either controlled or uncontrolled ' +
       '(specify either the checked prop, or the defaultChecked prop, but not ' +
       'both). Decide between using a controlled or uncontrolled input ' +
@@ -440,6 +441,7 @@ describe('ReactDOMInput', function() {
       <input type="text" value="foo" defaultValue="bar" readOnly={true} />
     );
     expect(console.error.argsForCall[0][0]).toContain(
+      'A component contains an input of type text with both value and defaultValue props. ' +
       'Input elements must be either controlled or uncontrolled ' +
       '(specify either the value prop, or the defaultValue prop, but not ' +
       'both). Decide between using a controlled or uncontrolled input ' +
@@ -488,7 +490,7 @@ describe('ReactDOMInput', function() {
     ReactDOM.render(<input type="text" value="controlled" />, container);
     expect(console.error.argsForCall.length).toBe(1);
     expect(console.error.argsForCall[0][0]).toContain(
-      'A component is changing a uncontrolled input of type text to be controlled. ' +
+      'A component is changing an uncontrolled input of type text to be controlled. ' +
       'Input elements should not switch from uncontrolled to controlled (or vice versa). ' +
       'Decide between using a controlled or uncontrolled input ' +
       'element for the lifetime of the component. More info: https://fb.me/react-controlled-components'
@@ -530,7 +532,7 @@ describe('ReactDOMInput', function() {
     ReactDOM.render(<input type="checkbox" checked={true} />, container);
     expect(console.error.argsForCall.length).toBe(1);
     expect(console.error.argsForCall[0][0]).toContain(
-      'A component is changing a uncontrolled input of type checkbox to be controlled. ' +
+      'A component is changing an uncontrolled input of type checkbox to be controlled. ' +
       'Input elements should not switch from uncontrolled to controlled (or vice versa). ' +
       'Decide between using a controlled or uncontrolled input ' +
       'element for the lifetime of the component. More info: https://fb.me/react-controlled-components'
@@ -572,7 +574,7 @@ describe('ReactDOMInput', function() {
     ReactDOM.render(<input type="radio" checked={true} />, container);
     expect(console.error.argsForCall.length).toBe(1);
     expect(console.error.argsForCall[0][0]).toContain(
-      'A component is changing a uncontrolled input of type radio to be controlled. ' +
+      'A component is changing an uncontrolled input of type radio to be controlled. ' +
       'Input elements should not switch from uncontrolled to controlled (or vice versa). ' +
       'Decide between using a controlled or uncontrolled input ' +
       'element for the lifetime of the component. More info: https://fb.me/react-controlled-components'
diff --git a/src/renderers/dom/client/wrappers/__tests__/ReactDOMSelect-test.js b/src/renderers/dom/client/wrappers/__tests__/ReactDOMSelect-test.js
index 0a3f530283..c4276c143f 100644
--- a/src/renderers/dom/client/wrappers/__tests__/ReactDOMSelect-test.js
+++ b/src/renderers/dom/client/wrappers/__tests__/ReactDOMSelect-test.js
@@ -348,7 +348,7 @@ describe('ReactDOMSelect', function() {
   });
 
   it('should support ReactLink', function() {
-    var link = new ReactLink('giraffe', jest.genMockFn());
+    var link = new ReactLink('giraffe', jest.fn());
     var stub =
       <select valueLink={link}>
         <option value="monkey">A monkey!</option>
diff --git a/src/renderers/dom/client/wrappers/__tests__/ReactDOMTextarea-test.js b/src/renderers/dom/client/wrappers/__tests__/ReactDOMTextarea-test.js
index 6a8f4d5d89..2a67d41c88 100644
--- a/src/renderers/dom/client/wrappers/__tests__/ReactDOMTextarea-test.js
+++ b/src/renderers/dom/client/wrappers/__tests__/ReactDOMTextarea-test.js
@@ -237,7 +237,7 @@ describe('ReactDOMTextarea', function() {
   });
 
   it('should support ReactLink', function() {
-    var link = new ReactLink('yolo', jest.genMockFn());
+    var link = new ReactLink('yolo', jest.fn());
     var instance = <textarea valueLink={link} />;
 
     spyOn(console, 'error');
diff --git a/src/renderers/dom/server/ReactServerRendering.js b/src/renderers/dom/server/ReactServerRendering.js
index 5a5d604b7d..ee57e07438 100644
--- a/src/renderers/dom/server/ReactServerRendering.js
+++ b/src/renderers/dom/server/ReactServerRendering.js
@@ -13,7 +13,9 @@
 var ReactDOMContainerInfo = require('ReactDOMContainerInfo');
 var ReactDefaultBatchingStrategy = require('ReactDefaultBatchingStrategy');
 var ReactElement = require('ReactElement');
+var ReactInstrumentation = require('ReactInstrumentation');
 var ReactMarkupChecksum = require('ReactMarkupChecksum');
+var ReactReconciler = require('ReactReconciler');
 var ReactServerBatchingStrategy = require('ReactServerBatchingStrategy');
 var ReactServerRenderingTransaction =
   require('ReactServerRenderingTransaction');
@@ -35,13 +37,23 @@ function renderToStringImpl(element, makeStaticMarkup) {
     transaction = ReactServerRenderingTransaction.getPooled(makeStaticMarkup);
 
     return transaction.perform(function() {
+      if (__DEV__) {
+        ReactInstrumentation.debugTool.onBeginFlush();
+      }
       var componentInstance = instantiateReactComponent(element);
-      var markup = componentInstance.mountComponent(
+      var markup = ReactReconciler.mountComponent(
+        componentInstance,
         transaction,
         null,
         ReactDOMContainerInfo(),
         emptyObject
       );
+      if (__DEV__) {
+        ReactInstrumentation.debugTool.onUnmountComponent(
+          componentInstance._debugID
+        );
+        ReactInstrumentation.debugTool.onEndFlush();
+      }
       if (!makeStaticMarkup) {
         markup = ReactMarkupChecksum.addChecksumToMarkup(markup);
       }
@@ -55,6 +67,11 @@ function renderToStringImpl(element, makeStaticMarkup) {
   }
 }
 
+/**
+ * Render a ReactElement to its initial HTML. This should only be used on the
+ * server.
+ * See https://facebook.github.io/react/docs/top-level-api.html#reactdomserver.rendertostring
+ */
 function renderToString(element) {
   invariant(
     ReactElement.isValidElement(element),
@@ -63,6 +80,11 @@ function renderToString(element) {
   return renderToStringImpl(element, false);
 }
 
+/**
+ * Similar to renderToString, except this doesn't create extra DOM attributes
+ * such as data-react-id that React uses internally.
+ * See https://facebook.github.io/react/docs/top-level-api.html#reactdomserver.rendertostaticmarkup
+ */
 function renderToStaticMarkup(element) {
   invariant(
     ReactElement.isValidElement(element),
diff --git a/src/renderers/dom/server/ReactServerRenderingTransaction.js b/src/renderers/dom/server/ReactServerRenderingTransaction.js
index 176a550c59..e7909eeeed 100644
--- a/src/renderers/dom/server/ReactServerRenderingTransaction.js
+++ b/src/renderers/dom/server/ReactServerRenderingTransaction.js
@@ -60,6 +60,12 @@ var Mixin = {
    */
   destructor: function() {
   },
+
+  checkpoint: function() {
+  },
+
+  rollback: function() {
+  },
 };
 
 
diff --git a/src/renderers/dom/server/__tests__/ReactServerRendering-test.js b/src/renderers/dom/server/__tests__/ReactServerRendering-test.js
index c53b0be742..c679e03793 100644
--- a/src/renderers/dom/server/__tests__/ReactServerRendering-test.js
+++ b/src/renderers/dom/server/__tests__/ReactServerRendering-test.js
@@ -86,7 +86,7 @@ describe('ReactServerRendering', function() {
 
     it('should not register event listeners', function() {
       var EventPluginHub = require('EventPluginHub');
-      var cb = jest.genMockFn();
+      var cb = jest.fn();
 
       ReactServerRendering.renderToString(
         <span onClick={cb}>hello world</span>
@@ -303,7 +303,7 @@ describe('ReactServerRendering', function() {
 
     it('should not register event listeners', function() {
       var EventPluginHub = require('EventPluginHub');
-      var cb = jest.genMockFn();
+      var cb = jest.fn();
 
       ReactServerRendering.renderToString(
         <span onClick={cb}>hello world</span>
diff --git a/src/renderers/dom/shared/CSSPropertyOperations.js b/src/renderers/dom/shared/CSSPropertyOperations.js
index aac1b75f87..4a16d050e6 100644
--- a/src/renderers/dom/shared/CSSPropertyOperations.js
+++ b/src/renderers/dom/shared/CSSPropertyOperations.js
@@ -13,7 +13,7 @@
 
 var CSSProperty = require('CSSProperty');
 var ExecutionEnvironment = require('ExecutionEnvironment');
-var ReactPerf = require('ReactPerf');
+var ReactInstrumentation = require('ReactInstrumentation');
 
 var camelizeStyleName = require('camelizeStyleName');
 var dangerousStyleValue = require('dangerousStyleValue');
@@ -192,6 +192,14 @@ var CSSPropertyOperations = {
    * @param {ReactDOMComponent} component
    */
   setValueForStyles: function(node, styles, component) {
+    if (__DEV__) {
+      ReactInstrumentation.debugTool.onNativeOperation(
+        component._debugID,
+        'update styles',
+        styles
+      );
+    }
+
     var style = node.style;
     for (var styleName in styles) {
       if (!styles.hasOwnProperty(styleName)) {
@@ -229,8 +237,4 @@ var CSSPropertyOperations = {
 
 };
 
-ReactPerf.measureMethods(CSSPropertyOperations, 'CSSPropertyOperations', {
-  setValueForStyles: 'setValueForStyles',
-});
-
 module.exports = CSSPropertyOperations;
diff --git a/src/renderers/dom/shared/DOMPropertyOperations.js b/src/renderers/dom/shared/DOMPropertyOperations.js
index 1ce9e29b75..eee9647ef6 100644
--- a/src/renderers/dom/shared/DOMPropertyOperations.js
+++ b/src/renderers/dom/shared/DOMPropertyOperations.js
@@ -12,8 +12,9 @@
 'use strict';
 
 var DOMProperty = require('DOMProperty');
+var ReactDOMComponentTree = require('ReactDOMComponentTree');
 var ReactDOMInstrumentation = require('ReactDOMInstrumentation');
-var ReactPerf = require('ReactPerf');
+var ReactInstrumentation = require('ReactInstrumentation');
 
 var quoteAttributeValueForBrowser = require('quoteAttributeValueForBrowser');
 var warning = require('warning');
@@ -134,9 +135,6 @@ var DOMPropertyOperations = {
    * @param {*} value
    */
   setValueForProperty: function(node, name, value) {
-    if (__DEV__) {
-      ReactDOMInstrumentation.debugTool.onSetValueForProperty(node, name, value);
-    }
     var propertyInfo = DOMProperty.properties.hasOwnProperty(name) ?
         DOMProperty.properties[name] : null;
     if (propertyInfo) {
@@ -145,6 +143,7 @@ var DOMPropertyOperations = {
         mutationMethod(node, value);
       } else if (shouldIgnoreValue(propertyInfo, value)) {
         this.deleteValueForProperty(node, name);
+        return;
       } else if (propertyInfo.mustUseProperty) {
         var propName = propertyInfo.propertyName;
         // Must explicitly cast values for HAS_SIDE_EFFECTS-properties to the
@@ -171,6 +170,18 @@ var DOMPropertyOperations = {
       }
     } else if (DOMProperty.isCustomAttribute(name)) {
       DOMPropertyOperations.setValueForAttribute(node, name, value);
+      return;
+    }
+
+    if (__DEV__) {
+      ReactDOMInstrumentation.debugTool.onSetValueForProperty(node, name, value);
+      var payload = {};
+      payload[name] = value;
+      ReactInstrumentation.debugTool.onNativeOperation(
+        ReactDOMComponentTree.getInstanceFromNode(node)._debugID,
+        'update attribute',
+        payload
+      );
     }
   },
 
@@ -183,6 +194,16 @@ var DOMPropertyOperations = {
     } else {
       node.setAttribute(name, '' + value);
     }
+
+    if (__DEV__) {
+      var payload = {};
+      payload[name] = value;
+      ReactInstrumentation.debugTool.onNativeOperation(
+        ReactDOMComponentTree.getInstanceFromNode(node)._debugID,
+        'update attribute',
+        payload
+      );
+    }
   },
 
   /**
@@ -192,9 +213,6 @@ var DOMPropertyOperations = {
    * @param {string} name
    */
   deleteValueForProperty: function(node, name) {
-    if (__DEV__) {
-      ReactDOMInstrumentation.debugTool.onDeleteValueForProperty(node, name);
-    }
     var propertyInfo = DOMProperty.properties.hasOwnProperty(name) ?
         DOMProperty.properties[name] : null;
     if (propertyInfo) {
@@ -218,14 +236,17 @@ var DOMPropertyOperations = {
     } else if (DOMProperty.isCustomAttribute(name)) {
       node.removeAttribute(name);
     }
+
+    if (__DEV__) {
+      ReactDOMInstrumentation.debugTool.onDeleteValueForProperty(node, name);
+      ReactInstrumentation.debugTool.onNativeOperation(
+        ReactDOMComponentTree.getInstanceFromNode(node)._debugID,
+        'remove attribute',
+        name
+      );
+    }
   },
 
 };
 
-ReactPerf.measureMethods(DOMPropertyOperations, 'DOMPropertyOperations', {
-  setValueForProperty: 'setValueForProperty',
-  setValueForAttribute: 'setValueForAttribute',
-  deleteValueForProperty: 'deleteValueForProperty',
-});
-
 module.exports = DOMPropertyOperations;
diff --git a/src/renderers/dom/shared/ReactComponentBrowserEnvironment.js b/src/renderers/dom/shared/ReactComponentBrowserEnvironment.js
index cf5df870d3..112c7d6241 100644
--- a/src/renderers/dom/shared/ReactComponentBrowserEnvironment.js
+++ b/src/renderers/dom/shared/ReactComponentBrowserEnvironment.js
@@ -13,7 +13,6 @@
 
 var DOMChildrenOperations = require('DOMChildrenOperations');
 var ReactDOMIDOperations = require('ReactDOMIDOperations');
-var ReactPerf = require('ReactPerf');
 
 /**
  * Abstracts away all functionality of the reconciler that requires knowledge of
@@ -40,12 +39,4 @@ var ReactComponentBrowserEnvironment = {
 
 };
 
-ReactPerf.measureMethods(
-  ReactComponentBrowserEnvironment,
-  'ReactComponentBrowserEnvironment',
-  {
-    replaceNodeWithMarkup: 'replaceNodeWithMarkup',
-  }
-);
-
 module.exports = ReactComponentBrowserEnvironment;
diff --git a/src/renderers/dom/shared/ReactDOMComponent.js b/src/renderers/dom/shared/ReactDOMComponent.js
index 445c9d8170..de393515b3 100644
--- a/src/renderers/dom/shared/ReactDOMComponent.js
+++ b/src/renderers/dom/shared/ReactDOMComponent.js
@@ -32,9 +32,11 @@ var ReactDOMInput = require('ReactDOMInput');
 var ReactDOMOption = require('ReactDOMOption');
 var ReactDOMSelect = require('ReactDOMSelect');
 var ReactDOMTextarea = require('ReactDOMTextarea');
+var ReactInstrumentation = require('ReactInstrumentation');
 var ReactMultiChild = require('ReactMultiChild');
-var ReactPerf = require('ReactPerf');
+var ReactServerRenderingTransaction = require('ReactServerRenderingTransaction');
 
+var emptyFunction = require('emptyFunction');
 var escapeTextContentForBrowser = require('escapeTextContentForBrowser');
 var invariant = require('invariant');
 var isEventSupported = require('isEventSupported');
@@ -207,6 +209,9 @@ function assertValidProps(component, props) {
 }
 
 function enqueuePutListener(inst, registrationName, listener, transaction) {
+  if (transaction instanceof ReactServerRenderingTransaction) {
+    return;
+  }
   if (__DEV__) {
     // IE8 has no API for event capturing and the `onScroll` event doesn't
     // bubble.
@@ -218,10 +223,6 @@ function enqueuePutListener(inst, registrationName, listener, transaction) {
   var containerInfo = inst._nativeContainerInfo;
   var isDocumentFragment = containerInfo._node && containerInfo._node.nodeType === DOC_FRAGMENT_TYPE;
   var doc = isDocumentFragment ? containerInfo._node : containerInfo._ownerDocument;
-  if (!doc) {
-    // Server rendering.
-    return;
-  }
   listenTo(registrationName, doc);
   transaction.getReactMountReady().enqueue(putListener, {
     inst: inst,
@@ -244,6 +245,19 @@ function optionPostMount() {
   ReactDOMOption.postMountWrapper(inst);
 }
 
+var setContentChildForInstrumentation = emptyFunction;
+if (__DEV__) {
+  setContentChildForInstrumentation = function(contentToUse) {
+    var debugID = this._debugID;
+    var contentDebugID = debugID + '#text';
+    this._contentDebugID = contentDebugID;
+    ReactInstrumentation.debugTool.onSetDisplayName(contentDebugID, '#text');
+    ReactInstrumentation.debugTool.onSetText(contentDebugID, '' + contentToUse);
+    ReactInstrumentation.debugTool.onMountComponent(contentDebugID);
+    ReactInstrumentation.debugTool.onSetChildren(debugID, [contentDebugID]);
+  };
+}
+
 // There are so many media events, it makes sense to just
 // maintain a list rather than create a `trapBubbledEvent` for each
 var mediaEvents = {
@@ -447,6 +461,7 @@ function ReactDOMComponent(element) {
   this._flags = 0;
   if (__DEV__) {
     this._ancestorInfo = null;
+    this._contentDebugID = null;
   }
 }
 
@@ -569,7 +584,7 @@ ReactDOMComponent.Mixin = {
           div.innerHTML = `<${type}></${type}>`;
           el = div.removeChild(div.firstChild);
         } else {
-          el = ownerDocument.createElement(this._currentElement.type);
+          el = ownerDocument.createElement(this._currentElement.type, props.is || null);
         }
       } else {
         el = ownerDocument.createElementNS(
@@ -710,6 +725,9 @@ ReactDOMComponent.Mixin = {
       if (contentToUse != null) {
         // TODO: Validate that text is allowed as a child of this node
         ret = escapeTextContentForBrowser(contentToUse);
+        if (__DEV__) {
+          setContentChildForInstrumentation.call(this, contentToUse);
+        }
       } else if (childrenToUse != null) {
         var mountImages = this.mountChildren(
           childrenToUse,
@@ -749,6 +767,9 @@ ReactDOMComponent.Mixin = {
       var childrenToUse = contentToUse != null ? null : props.children;
       if (contentToUse != null) {
         // TODO: Validate that text is allowed as a child of this node
+        if (__DEV__) {
+          setContentChildForInstrumentation.call(this, contentToUse);
+        }
         DOMLazyTree.queueText(lazyTree, contentToUse);
       } else if (childrenToUse != null) {
         var mountImages = this.mountChildren(
@@ -996,17 +1017,34 @@ ReactDOMComponent.Mixin = {
       this.updateChildren(null, transaction, context);
     } else if (lastHasContentOrHtml && !nextHasContentOrHtml) {
       this.updateTextContent('');
+      if (__DEV__) {
+        ReactInstrumentation.debugTool.onSetChildren(this._debugID, []);
+      }
     }
 
     if (nextContent != null) {
       if (lastContent !== nextContent) {
         this.updateTextContent('' + nextContent);
+        if (__DEV__) {
+          this._contentDebugID = this._debugID + '#text';
+          setContentChildForInstrumentation.call(this, nextContent);
+        }
       }
     } else if (nextHtml != null) {
       if (lastHtml !== nextHtml) {
         this.updateMarkup('' + nextHtml);
       }
+      if (__DEV__) {
+        ReactInstrumentation.debugTool.onSetChildren(this._debugID, []);
+      }
     } else if (nextChildren != null) {
+      if (__DEV__) {
+        if (this._contentDebugID) {
+          ReactInstrumentation.debugTool.onUnmountComponent(this._contentDebugID);
+          this._contentDebugID = null;
+        }
+      }
+
       this.updateChildren(nextChildren, transaction, context);
     }
   },
@@ -1064,6 +1102,13 @@ ReactDOMComponent.Mixin = {
     this._rootNodeID = null;
     this._domID = null;
     this._wrapperState = null;
+
+    if (__DEV__) {
+      if (this._contentDebugID) {
+        ReactInstrumentation.debugTool.onUnmountComponent(this._contentDebugID);
+        this._contentDebugID = null;
+      }
+    }
   },
 
   getPublicInstance: function() {
@@ -1072,11 +1117,6 @@ ReactDOMComponent.Mixin = {
 
 };
 
-ReactPerf.measureMethods(ReactDOMComponent.Mixin, 'ReactDOMComponent', {
-  mountComponent: 'mountComponent',
-  receiveComponent: 'receiveComponent',
-});
-
 Object.assign(
   ReactDOMComponent.prototype,
   ReactDOMComponent.Mixin,
diff --git a/src/renderers/dom/shared/ReactDOMTextComponent.js b/src/renderers/dom/shared/ReactDOMTextComponent.js
index 9a69c7f977..a46c188930 100644
--- a/src/renderers/dom/shared/ReactDOMTextComponent.js
+++ b/src/renderers/dom/shared/ReactDOMTextComponent.js
@@ -14,7 +14,7 @@
 var DOMChildrenOperations = require('DOMChildrenOperations');
 var DOMLazyTree = require('DOMLazyTree');
 var ReactDOMComponentTree = require('ReactDOMComponentTree');
-var ReactPerf = require('ReactPerf');
+var ReactInstrumentation = require('ReactInstrumentation');
 
 var escapeTextContentForBrowser = require('escapeTextContentForBrowser');
 var invariant = require('invariant');
@@ -67,6 +67,8 @@ Object.assign(ReactDOMTextComponent.prototype, {
     context
   ) {
     if (__DEV__) {
+      ReactInstrumentation.debugTool.onSetText(this._debugID, this._stringText);
+
       var parentInfo;
       if (nativeParent != null) {
         parentInfo = nativeParent._ancestorInfo;
@@ -140,6 +142,13 @@ Object.assign(ReactDOMTextComponent.prototype, {
           commentNodes[1],
           nextStringText
         );
+
+        if (__DEV__) {
+          ReactInstrumentation.debugTool.onSetText(
+            this._debugID,
+            nextStringText
+          );
+        }
       }
     }
   },
@@ -178,13 +187,4 @@ Object.assign(ReactDOMTextComponent.prototype, {
 
 });
 
-ReactPerf.measureMethods(
-  ReactDOMTextComponent.prototype,
-  'ReactDOMTextComponent',
-  {
-    mountComponent: 'mountComponent',
-    receiveComponent: 'receiveComponent',
-  }
-);
-
 module.exports = ReactDOMTextComponent;
diff --git a/src/renderers/dom/shared/ReactDefaultInjection.js b/src/renderers/dom/shared/ReactDefaultInjection.js
index 09cbf25e48..f71a9b9dab 100644
--- a/src/renderers/dom/shared/ReactDefaultInjection.js
+++ b/src/renderers/dom/shared/ReactDefaultInjection.js
@@ -15,7 +15,6 @@ var BeforeInputEventPlugin = require('BeforeInputEventPlugin');
 var ChangeEventPlugin = require('ChangeEventPlugin');
 var DefaultEventPluginOrder = require('DefaultEventPluginOrder');
 var EnterLeaveEventPlugin = require('EnterLeaveEventPlugin');
-var ExecutionEnvironment = require('ExecutionEnvironment');
 var HTMLDOMPropertyConfig = require('HTMLDOMPropertyConfig');
 var ReactComponentBrowserEnvironment =
   require('ReactComponentBrowserEnvironment');
@@ -91,14 +90,6 @@ function inject() {
   );
 
   ReactInjection.Component.injectEnvironment(ReactComponentBrowserEnvironment);
-
-  if (__DEV__) {
-    var url = (ExecutionEnvironment.canUseDOM && window.location.href) || '';
-    if ((/[?&]react_perf\b/).test(url)) {
-      var ReactDefaultPerf = require('ReactDefaultPerf');
-      ReactDefaultPerf.start();
-    }
-  }
 }
 
 module.exports = {
diff --git a/src/renderers/dom/shared/ReactInjection.js b/src/renderers/dom/shared/ReactInjection.js
index 26085eb2f7..51fb065518 100644
--- a/src/renderers/dom/shared/ReactInjection.js
+++ b/src/renderers/dom/shared/ReactInjection.js
@@ -19,7 +19,6 @@ var ReactClass = require('ReactClass');
 var ReactEmptyComponent = require('ReactEmptyComponent');
 var ReactBrowserEventEmitter = require('ReactBrowserEventEmitter');
 var ReactNativeComponent = require('ReactNativeComponent');
-var ReactPerf = require('ReactPerf');
 var ReactUpdates = require('ReactUpdates');
 
 var ReactInjection = {
@@ -31,7 +30,6 @@ var ReactInjection = {
   EventPluginUtils: EventPluginUtils.injection,
   EventEmitter: ReactBrowserEventEmitter.injection,
   NativeComponent: ReactNativeComponent.injection,
-  Perf: ReactPerf.injection,
   Updates: ReactUpdates.injection,
 };
 
diff --git a/src/renderers/dom/shared/__tests__/DOMPropertyOperations-test.js b/src/renderers/dom/shared/__tests__/DOMPropertyOperations-test.js
index 14b72282ae..4200d37678 100644
--- a/src/renderers/dom/shared/__tests__/DOMPropertyOperations-test.js
+++ b/src/renderers/dom/shared/__tests__/DOMPropertyOperations-test.js
@@ -14,6 +14,7 @@
 describe('DOMPropertyOperations', function() {
   var DOMPropertyOperations;
   var DOMProperty;
+  var ReactDOMComponentTree;
 
   beforeEach(function() {
     jest.resetModuleRegistry();
@@ -22,6 +23,7 @@ describe('DOMPropertyOperations', function() {
 
     DOMPropertyOperations = require('DOMPropertyOperations');
     DOMProperty = require('DOMProperty');
+    ReactDOMComponentTree = require('ReactDOMComponentTree');
   });
 
   describe('createMarkupForProperty', function() {
@@ -172,9 +174,12 @@ describe('DOMPropertyOperations', function() {
 
   describe('setValueForProperty', function() {
     var stubNode;
+    var stubInstance;
 
     beforeEach(function() {
       stubNode = document.createElement('div');
+      stubInstance = {_debugID: 1};
+      ReactDOMComponentTree.precacheNode(stubInstance, stubNode);
     });
 
     it('should set values as properties by default', function() {
@@ -223,6 +228,8 @@ describe('DOMPropertyOperations', function() {
 
     it('should not remove empty attributes for special properties', function() {
       stubNode = document.createElement('input');
+      ReactDOMComponentTree.precacheNode(stubInstance, stubNode);
+
       DOMPropertyOperations.setValueForProperty(stubNode, 'value', '');
       // JSDOM does not behave correctly for attributes/properties
       //expect(stubNode.getAttribute('value')).toBe('');
@@ -254,7 +261,7 @@ describe('DOMPropertyOperations', function() {
     });
 
     it('should use mutation method where applicable', function() {
-      var foobarSetter = jest.genMockFn();
+      var foobarSetter = jest.fn();
       // inject foobar DOM property
       DOMProperty.injection.injectDOMPropertyConfig({
         Properties: {foobar: null},
@@ -343,9 +350,12 @@ describe('DOMPropertyOperations', function() {
 
   describe('deleteValueForProperty', function() {
     var stubNode;
+    var stubInstance;
 
     beforeEach(function() {
       stubNode = document.createElement('div');
+      stubInstance = {_debugID: 1};
+      ReactDOMComponentTree.precacheNode(stubInstance, stubNode);
     });
 
     it('should remove attributes for normal properties', function() {
@@ -361,6 +371,8 @@ describe('DOMPropertyOperations', function() {
 
     it('should not remove attributes for special properties', function() {
       stubNode = document.createElement('input');
+      ReactDOMComponentTree.precacheNode(stubInstance, stubNode);
+
       stubNode.setAttribute('value', 'foo');
 
       DOMPropertyOperations.deleteValueForProperty(stubNode, 'value');
@@ -371,6 +383,8 @@ describe('DOMPropertyOperations', function() {
 
     it('should not leave all options selected when deleting multiple', function() {
       stubNode = document.createElement('select');
+      ReactDOMComponentTree.precacheNode(stubInstance, stubNode);
+
       stubNode.multiple = true;
       stubNode.appendChild(document.createElement('option'));
       stubNode.appendChild(document.createElement('option'));
diff --git a/src/renderers/dom/shared/__tests__/ReactDOMComponent-test.js b/src/renderers/dom/shared/__tests__/ReactDOMComponent-test.js
index d009ed80d0..18581f316c 100644
--- a/src/renderers/dom/shared/__tests__/ReactDOMComponent-test.js
+++ b/src/renderers/dom/shared/__tests__/ReactDOMComponent-test.js
@@ -15,12 +15,14 @@
 describe('ReactDOMComponent', function() {
   var React;
   var ReactDOM;
+  var ReactDOMFeatureFlags;
   var ReactDOMServer;
 
   beforeEach(function() {
     jest.resetModuleRegistry();
     React = require('React');
     ReactDOM = require('ReactDOM');
+    ReactDOMFeatureFlags = require('ReactDOMFeatureFlags');
     ReactDOMServer = require('ReactDOMServer');
   });
 
@@ -448,11 +450,11 @@ describe('ReactDOMComponent', function() {
 
       var node = container.firstChild;
       var nodeSetAttribute = node.setAttribute;
-      node.setAttribute = jest.genMockFn();
+      node.setAttribute = jest.fn();
       node.setAttribute.mockImpl(nodeSetAttribute);
 
       var nodeRemoveAttribute = node.removeAttribute;
-      node.removeAttribute = jest.genMockFn();
+      node.removeAttribute = jest.fn();
       node.removeAttribute.mockImpl(nodeRemoveAttribute);
 
       ReactDOM.render(<div id="" />, container);
@@ -486,7 +488,7 @@ describe('ReactDOMComponent', function() {
 
       var node = container.firstChild;
       var nodeValue = ''; // node.value always returns undefined
-      var nodeValueSetter = jest.genMockFn();
+      var nodeValueSetter = jest.fn();
       Object.defineProperty(node, 'value', {
         get: function() {
           return nodeValue;
@@ -517,7 +519,7 @@ describe('ReactDOMComponent', function() {
 
       var node = container.firstChild;
       var nodeValue = true;
-      var nodeValueSetter = jest.genMockFn();
+      var nodeValueSetter = jest.fn();
       Object.defineProperty(node, 'checked', {
         get: function() {
           return nodeValue;
@@ -550,7 +552,7 @@ describe('ReactDOMComponent', function() {
       var container = document.createElement('div');
       var node = ReactDOM.render(<div />, container);
 
-      var setter = jest.genMockFn();
+      var setter = jest.fn();
       node.setAttribute = setter;
 
       ReactDOM.render(<div dir={null} />, container);
@@ -819,8 +821,8 @@ describe('ReactDOMComponent', function() {
     it('should execute custom event plugin listening behavior', function() {
       var SimpleEventPlugin = require('SimpleEventPlugin');
 
-      SimpleEventPlugin.didPutListener = jest.genMockFn();
-      SimpleEventPlugin.willDeleteListener = jest.genMockFn();
+      SimpleEventPlugin.didPutListener = jest.fn();
+      SimpleEventPlugin.willDeleteListener = jest.fn();
 
       var container = document.createElement('div');
       ReactDOM.render(
@@ -838,8 +840,8 @@ describe('ReactDOMComponent', function() {
     it('should handle null and missing properly with event hooks', function() {
       var SimpleEventPlugin = require('SimpleEventPlugin');
 
-      SimpleEventPlugin.didPutListener = jest.genMockFn();
-      SimpleEventPlugin.willDeleteListener = jest.genMockFn();
+      SimpleEventPlugin.didPutListener = jest.fn();
+      SimpleEventPlugin.willDeleteListener = jest.fn();
       var container = document.createElement('div');
 
       ReactDOM.render(<div onClick={false} />, container);
@@ -886,6 +888,17 @@ describe('ReactDOMComponent', function() {
         'or use `props.dangerouslySetInnerHTML`. Check the render method of X.'
       );
     });
+
+    it('should support custom elements which extend native elements', function() {
+      if (ReactDOMFeatureFlags.useCreateElement) {
+        var container = document.createElement('div');
+        spyOn(document, 'createElement').andCallThrough();
+        ReactDOM.render(<div is="custom-div" />, container);
+        expect(document.createElement).toHaveBeenCalledWith('div', 'custom-div');
+      } else {
+        expect(ReactDOMServer.renderToString(<div is="custom-div" />)).toContain('is="custom-div"');
+      }
+    });
   });
 
   describe('updateComponent', function() {
@@ -1050,6 +1063,12 @@ describe('ReactDOMComponent', function() {
         'Warning: This browser doesn\'t support the `onScroll` event'
       );
     });
+
+    it('should not warn when server-side rendering `onScroll`', function() {
+      spyOn(console, 'error');
+      ReactDOMServer.renderToString(<div onScroll={() => {}}/>);
+      expect(console.error).not.toHaveBeenCalled();
+    });
   });
 
   describe('tag sanitization', function() {
diff --git a/src/renderers/native/ReactIOS/NativeMethodsMixin.js b/src/renderers/native/NativeMethodsMixin.js
similarity index 100%
rename from src/renderers/native/ReactIOS/NativeMethodsMixin.js
rename to src/renderers/native/NativeMethodsMixin.js
diff --git a/src/renderers/native/ReactNative/ReactNative.js b/src/renderers/native/ReactNative.js
similarity index 100%
rename from src/renderers/native/ReactNative/ReactNative.js
rename to src/renderers/native/ReactNative.js
diff --git a/src/renderers/native/ReactNative/__mocks__/JSTimersExecution.js b/src/renderers/native/ReactNative/__mocks__/JSTimersExecution.js
deleted file mode 100644
index 3f4b4fdd0f..0000000000
--- a/src/renderers/native/ReactNative/__mocks__/JSTimersExecution.js
+++ /dev/null
@@ -1,14 +0,0 @@
-/**
- * Copyright 2013-2015, Facebook, Inc.
- * All rights reserved.
- *
- * This source code is licensed under the BSD-style license found in the
- * LICENSE file in the root directory of this source tree. An additional grant
- * of patent rights can be found in the PATENTS file in the same directory.
- */
-
-'use strict';
-
-// Noop
-
-// TODO: Move all initialization callers back into react-native
diff --git a/src/renderers/native/ReactNative/__mocks__/Platform.js b/src/renderers/native/ReactNative/__mocks__/Platform.js
deleted file mode 100644
index fc04c24549..0000000000
--- a/src/renderers/native/ReactNative/__mocks__/Platform.js
+++ /dev/null
@@ -1,16 +0,0 @@
-/**
- * Copyright 2013-2015, Facebook, Inc.
- * All rights reserved.
- *
- * This source code is licensed under the BSD-style license found in the
- * LICENSE file in the root directory of this source tree. An additional grant
- * of patent rights can be found in the PATENTS file in the same directory.
- */
-
-'use strict';
-
-// Mock of the Native Hooks
-
-var Platform = {};
-
-module.exports = Platform;
diff --git a/src/renderers/native/ReactNative/__mocks__/RCTLog.js b/src/renderers/native/ReactNative/__mocks__/RCTLog.js
deleted file mode 100644
index 3f4b4fdd0f..0000000000
--- a/src/renderers/native/ReactNative/__mocks__/RCTLog.js
+++ /dev/null
@@ -1,14 +0,0 @@
-/**
- * Copyright 2013-2015, Facebook, Inc.
- * All rights reserved.
- *
- * This source code is licensed under the BSD-style license found in the
- * LICENSE file in the root directory of this source tree. An additional grant
- * of patent rights can be found in the PATENTS file in the same directory.
- */
-
-'use strict';
-
-// Noop
-
-// TODO: Move all initialization callers back into react-native
diff --git a/src/renderers/native/ReactNative/__mocks__/InteractionManager.js b/src/renderers/native/ReactNative/__mocks__/View.js
similarity index 61%
rename from src/renderers/native/ReactNative/__mocks__/InteractionManager.js
rename to src/renderers/native/ReactNative/__mocks__/View.js
index de72e164a6..71856da167 100644
--- a/src/renderers/native/ReactNative/__mocks__/InteractionManager.js
+++ b/src/renderers/native/ReactNative/__mocks__/View.js
@@ -9,8 +9,11 @@
 
 'use strict';
 
-// TODO: Figure out a way to drop this dependency
+var createReactNativeComponentClass = require('createReactNativeComponentClass');
 
-var InteractionManager = {};
+var View = createReactNativeComponentClass({
+  validAttributes: {},
+  uiViewClassName: 'View',
+});
 
-module.exports = InteractionManager;
+module.exports = View;
diff --git a/src/renderers/native/ReactNative/__mocks__/merge.js b/src/renderers/native/ReactNative/__mocks__/merge.js
deleted file mode 100644
index 0c2dc8bf5d..0000000000
--- a/src/renderers/native/ReactNative/__mocks__/merge.js
+++ /dev/null
@@ -1,18 +0,0 @@
-/**
- * Copyright 2013-2015, Facebook, Inc.
- * All rights reserved.
- *
- * This source code is licensed under the BSD-style license found in the
- * LICENSE file in the root directory of this source tree. An additional grant
- * of patent rights can be found in the PATENTS file in the same directory.
- */
-
-'use strict';
-
-// TODO: Replace all callers with spread
-
-var merge = function(a, b) {
-  return {...a, ...b};
-};
-
-module.exports = merge;
diff --git a/src/renderers/native/ReactNative/ReactNativeAttributePayload.js b/src/renderers/native/ReactNativeAttributePayload.js
similarity index 91%
rename from src/renderers/native/ReactNative/ReactNativeAttributePayload.js
rename to src/renderers/native/ReactNativeAttributePayload.js
index ca1cd57030..a2976c6025 100644
--- a/src/renderers/native/ReactNative/ReactNativeAttributePayload.js
+++ b/src/renderers/native/ReactNativeAttributePayload.js
@@ -11,7 +11,6 @@
  */
 'use strict';
 
-var Platform = require('Platform');
 var ReactNativePropRegistry = require('ReactNativePropRegistry');
 
 var deepDiffer = require('deepDiffer');
@@ -47,21 +46,6 @@ type NestedNode = Array<NestedNode> | Object | number;
 var removedKeys = null;
 var removedKeyCount = 0;
 
-function translateKey(propKey: string) : string {
-  if (propKey === 'transform') {
-    // We currently special case the key for `transform`. iOS uses the
-    // transformMatrix name and Android uses the decomposedMatrix name.
-    // TODO: We could unify these names and just use the name `transform`
-    // all the time. Just need to update the native side.
-    if (Platform.OS === 'android') {
-      return 'decomposedMatrix';
-    } else {
-      return 'transformMatrix';
-    }
-  }
-  return propKey;
-}
-
 function defaultDiffer(prevProp: mixed, nextProp: mixed) : boolean {
   if (typeof nextProp !== 'object' || nextProp === null) {
     // Scalars have already been checked for equality
@@ -326,7 +310,6 @@ function diffProperties(
   var attributeConfig : ?(CustomAttributeConfiguration | AttributeConfiguration);
   var nextProp;
   var prevProp;
-  var altKey;
 
   for (var propKey in nextProps) {
     attributeConfig = validAttributes[propKey];
@@ -334,12 +317,6 @@ function diffProperties(
       continue; // not a valid native prop
     }
 
-    altKey = translateKey(propKey);
-    if (!validAttributes[altKey]) {
-      // If there is no config for the alternative, bail out. Helps ART.
-      altKey = propKey;
-    }
-
     prevProp = prevProps[propKey];
     nextProp = nextProps[propKey];
 
@@ -367,7 +344,7 @@ function diffProperties(
       removedKeys[propKey] = false;
     }
 
-    if (updatePayload && updatePayload[altKey] !== undefined) {
+    if (updatePayload && updatePayload[propKey] !== undefined) {
       // Something else already triggered an update to this key because another
       // value diffed. Since we're now later in the nested arrays our value is
       // more important so we need to calculate it and override the existing
@@ -376,14 +353,14 @@ function diffProperties(
       // Pattern match on: attributeConfig
       if (typeof attributeConfig !== 'object') {
         // case: !Object is the default case
-        updatePayload[altKey] = nextProp;
+        updatePayload[propKey] = nextProp;
       } else if (typeof attributeConfig.diff === 'function' ||
                  typeof attributeConfig.process === 'function') {
         // case: CustomAttributeConfiguration
         var nextValue = typeof attributeConfig.process === 'function' ?
                         attributeConfig.process(nextProp) :
                         nextProp;
-        updatePayload[altKey] = nextValue;
+        updatePayload[propKey] = nextValue;
       }
       continue;
     }
@@ -397,7 +374,7 @@ function diffProperties(
       // case: !Object is the default case
       if (defaultDiffer(prevProp, nextProp)) {
         // a normal leaf has changed
-        (updatePayload || (updatePayload = {}))[altKey] = nextProp;
+        (updatePayload || (updatePayload = {}))[propKey] = nextProp;
       }
     } else if (typeof attributeConfig.diff === 'function' ||
                typeof attributeConfig.process === 'function') {
@@ -411,7 +388,7 @@ function diffProperties(
         nextValue = typeof attributeConfig.process === 'function' ?
                     attributeConfig.process(nextProp) :
                     nextProp;
-        (updatePayload || (updatePayload = {}))[altKey] = nextValue;
+        (updatePayload || (updatePayload = {}))[propKey] = nextValue;
       }
     } else {
       // default: fallthrough case when nested properties are defined
@@ -446,13 +423,7 @@ function diffProperties(
       continue; // not a valid native prop
     }
 
-    altKey = translateKey(propKey);
-    if (!attributeConfig[altKey]) {
-      // If there is no config for the alternative, bail out. Helps ART.
-      altKey = propKey;
-    }
-
-    if (updatePayload && updatePayload[altKey] !== undefined) {
+    if (updatePayload && updatePayload[propKey] !== undefined) {
       // This was already updated to a diff result earlier.
       continue;
     }
@@ -468,7 +439,7 @@ function diffProperties(
 
       // case: CustomAttributeConfiguration | !Object
       // Flag the leaf property for removal by sending a sentinel.
-      (updatePayload || (updatePayload = {}))[altKey] = null;
+      (updatePayload || (updatePayload = {}))[propKey] = null;
       if (!removedKeys) {
         removedKeys = {};
       }
diff --git a/src/renderers/native/ReactNative/ReactNativeBaseComponent.js b/src/renderers/native/ReactNativeBaseComponent.js
similarity index 100%
rename from src/renderers/native/ReactNative/ReactNativeBaseComponent.js
rename to src/renderers/native/ReactNativeBaseComponent.js
diff --git a/src/renderers/native/ReactIOS/IOSNativeBridgeEventPlugin.js b/src/renderers/native/ReactNativeBridgeEventPlugin.js
similarity index 88%
rename from src/renderers/native/ReactIOS/IOSNativeBridgeEventPlugin.js
rename to src/renderers/native/ReactNativeBridgeEventPlugin.js
index 564e10f28c..97c6496c6a 100644
--- a/src/renderers/native/ReactIOS/IOSNativeBridgeEventPlugin.js
+++ b/src/renderers/native/ReactNativeBridgeEventPlugin.js
@@ -6,7 +6,7 @@
  * LICENSE file in the root directory of this source tree. An additional grant
  * of patent rights can be found in the PATENTS file in the same directory.
  *
- * @providesModule IOSNativeBridgeEventPlugin
+ * @providesModule ReactNativeBridgeEventPlugin
  * @flow
  */
 'use strict';
@@ -15,7 +15,6 @@ var EventPropagators = require('EventPropagators');
 var SyntheticEvent = require('SyntheticEvent');
 var UIManager = require('UIManager');
 
-var merge = require('merge');
 var warning = require('warning');
 
 var customBubblingEventTypes = UIManager.customBubblingEventTypes;
@@ -36,9 +35,9 @@ for (var directTypeName in customDirectEventTypes) {
   allTypesByEventName[directTypeName] = customDirectEventTypes[directTypeName];
 }
 
-var IOSNativeBridgeEventPlugin = {
+var ReactNativeBridgeEventPlugin = {
 
-  eventTypes: merge(customBubblingEventTypes, customDirectEventTypes),
+  eventTypes: { ...customBubblingEventTypes, ...customDirectEventTypes },
 
   /**
    * @see {EventPluginHub.extractEvents}
@@ -68,4 +67,4 @@ var IOSNativeBridgeEventPlugin = {
   },
 };
 
-module.exports = IOSNativeBridgeEventPlugin;
+module.exports = ReactNativeBridgeEventPlugin;
diff --git a/src/renderers/native/ReactNative/ReactNativeComponentEnvironment.js b/src/renderers/native/ReactNativeComponentEnvironment.js
similarity index 100%
rename from src/renderers/native/ReactNative/ReactNativeComponentEnvironment.js
rename to src/renderers/native/ReactNativeComponentEnvironment.js
diff --git a/src/renderers/native/ReactNative/ReactNativeComponentTree.js b/src/renderers/native/ReactNativeComponentTree.js
similarity index 100%
rename from src/renderers/native/ReactNative/ReactNativeComponentTree.js
rename to src/renderers/native/ReactNativeComponentTree.js
diff --git a/src/renderers/native/ReactNative/ReactNativeContainerInfo.js b/src/renderers/native/ReactNativeContainerInfo.js
similarity index 100%
rename from src/renderers/native/ReactNative/ReactNativeContainerInfo.js
rename to src/renderers/native/ReactNativeContainerInfo.js
diff --git a/src/renderers/native/ReactNative/ReactNativeDOMIDOperations.js b/src/renderers/native/ReactNativeDOMIDOperations.js
similarity index 83%
rename from src/renderers/native/ReactNative/ReactNativeDOMIDOperations.js
rename to src/renderers/native/ReactNativeDOMIDOperations.js
index 0bb92fef55..8d07d2d6ab 100644
--- a/src/renderers/native/ReactNative/ReactNativeDOMIDOperations.js
+++ b/src/renderers/native/ReactNativeDOMIDOperations.js
@@ -13,7 +13,6 @@
 
 var ReactNativeComponentTree = require('ReactNativeComponentTree');
 var ReactMultiChildUpdateTypes = require('ReactMultiChildUpdateTypes');
-var ReactPerf = require('ReactPerf');
 var UIManager = require('UIManager');
 
 /**
@@ -71,12 +70,7 @@ var dangerouslyProcessChildrenUpdates = function(inst, childrenUpdates) {
  * `ReactComponent.DOMIDOperations`.
  */
 var ReactNativeDOMIDOperations = {
-  dangerouslyProcessChildrenUpdates: ReactPerf.measure(
-    // FIXME(frantic): #4441289 Hack to avoid modifying react-tools
-    'ReactDOMIDOperations',
-    'dangerouslyProcessChildrenUpdates',
-    dangerouslyProcessChildrenUpdates
-  ),
+  dangerouslyProcessChildrenUpdates,
 
   /**
    * Replaces a view that exists in the document with markup.
@@ -84,14 +78,10 @@ var ReactNativeDOMIDOperations = {
    * @param {string} id ID of child to be replaced.
    * @param {string} markup Mount image to replace child with id.
    */
-  dangerouslyReplaceNodeWithMarkupByID: ReactPerf.measure(
-    'ReactDOMIDOperations',
-    'dangerouslyReplaceNodeWithMarkupByID',
-    function(id, mountImage) {
-      var oldTag = id;
-      UIManager.replaceExistingNonRootView(oldTag, mountImage);
-    }
-  ),
+  dangerouslyReplaceNodeWithMarkupByID: function(id, mountImage) {
+    var oldTag = id;
+    UIManager.replaceExistingNonRootView(oldTag, mountImage);
+  },
 };
 
 module.exports = ReactNativeDOMIDOperations;
diff --git a/src/renderers/native/ReactNative/ReactNativeDefaultInjection.js b/src/renderers/native/ReactNativeDefaultInjection.js
similarity index 85%
rename from src/renderers/native/ReactNative/ReactNativeDefaultInjection.js
rename to src/renderers/native/ReactNativeDefaultInjection.js
index c0c5fd2073..be8a5625ea 100644
--- a/src/renderers/native/ReactNative/ReactNativeDefaultInjection.js
+++ b/src/renderers/native/ReactNativeDefaultInjection.js
@@ -15,39 +15,42 @@
  * Make sure essential globals are available and are patched correctly. Please don't remove this
  * line. Bundles created by react-packager `require` it before executing any application code. This
  * ensures it exists in the dependency graph and can be `require`d.
+ * TODO: require this in packager, not in React #10932517
  */
 require('InitializeJavaScriptAppEngine');
 
 var EventPluginHub = require('EventPluginHub');
 var EventPluginUtils = require('EventPluginUtils');
-var IOSDefaultEventPluginOrder = require('IOSDefaultEventPluginOrder');
-var IOSNativeBridgeEventPlugin = require('IOSNativeBridgeEventPlugin');
-var ReactElement = require('ReactElement');
+var RCTEventEmitter = require('RCTEventEmitter');
 var ReactComponentEnvironment = require('ReactComponentEnvironment');
 var ReactDefaultBatchingStrategy = require('ReactDefaultBatchingStrategy');
+var ReactElement = require('ReactElement');
 var ReactEmptyComponent = require('ReactEmptyComponent');
+var ReactNativeBridgeEventPlugin = require('ReactNativeBridgeEventPlugin');
+var ReactNativeComponent = require('ReactNativeComponent');
 var ReactNativeComponentEnvironment = require('ReactNativeComponentEnvironment');
+var ReactNativeComponentTree = require('ReactNativeComponentTree');
+var ReactNativeEventEmitter = require('ReactNativeEventEmitter');
+var ReactNativeEventPluginOrder = require('ReactNativeEventPluginOrder');
 var ReactNativeGlobalResponderHandler = require('ReactNativeGlobalResponderHandler');
 var ReactNativeTextComponent = require('ReactNativeTextComponent');
 var ReactNativeTreeTraversal = require('ReactNativeTreeTraversal');
-var ReactNativeComponent = require('ReactNativeComponent');
-var ReactNativeComponentTree = require('ReactNativeComponentTree');
 var ReactSimpleEmptyComponent = require('ReactSimpleEmptyComponent');
 var ReactUpdates = require('ReactUpdates');
 var ResponderEventPlugin = require('ResponderEventPlugin');
 
 var invariant = require('invariant');
 
-// Just to ensure this gets packaged, since its only caller is from Native.
-require('RCTEventEmitter');
-require('RCTLog');
-require('JSTimersExecution');
-
 function inject() {
+  /**
+   * Register the event emitter with the native bridge
+   */
+  RCTEventEmitter.register(ReactNativeEventEmitter);
+
   /**
    * Inject module for resolving DOM hierarchy and plugin ordering.
    */
-  EventPluginHub.injection.injectEventPluginOrder(IOSDefaultEventPluginOrder);
+  EventPluginHub.injection.injectEventPluginOrder(ReactNativeEventPluginOrder);
   EventPluginUtils.injection.injectComponentTree(ReactNativeComponentTree);
   EventPluginUtils.injection.injectTreeTraversal(ReactNativeTreeTraversal);
 
@@ -61,7 +64,7 @@ function inject() {
    */
   EventPluginHub.injection.injectEventPluginsByName({
     'ResponderEventPlugin': ResponderEventPlugin,
-    'IOSNativeBridgeEventPlugin': IOSNativeBridgeEventPlugin,
+    'ReactNativeBridgeEventPlugin': ReactNativeBridgeEventPlugin,
   });
 
   ReactUpdates.injection.injectReconcileTransaction(
diff --git a/src/renderers/native/ReactNative/ReactNativeEventEmitter.js b/src/renderers/native/ReactNativeEventEmitter.js
similarity index 98%
rename from src/renderers/native/ReactNative/ReactNativeEventEmitter.js
rename to src/renderers/native/ReactNativeEventEmitter.js
index bf7179c2ae..699b092697 100644
--- a/src/renderers/native/ReactNative/ReactNativeEventEmitter.js
+++ b/src/renderers/native/ReactNativeEventEmitter.js
@@ -11,15 +11,14 @@
  */
 'use strict';
 
+var EventConstants = require('EventConstants');
 var EventPluginHub = require('EventPluginHub');
 var EventPluginRegistry = require('EventPluginRegistry');
 var ReactEventEmitterMixin = require('ReactEventEmitterMixin');
 var ReactNativeComponentTree = require('ReactNativeComponentTree');
 var ReactNativeTagHandles = require('ReactNativeTagHandles');
 var ReactUpdates = require('ReactUpdates');
-var EventConstants = require('EventConstants');
 
-var merge = require('merge');
 var warning = require('warning');
 
 var topLevelTypes = EventConstants.topLevelTypes;
@@ -91,7 +90,9 @@ var removeTouchesAtIndices = function(
  *
  * @internal
  */
-var ReactNativeEventEmitter = merge(ReactEventEmitterMixin, {
+var ReactNativeEventEmitter = {
+
+  ...ReactEventEmitterMixin,
 
   registrationNames: EventPluginRegistry.registrationNameModules,
 
@@ -218,6 +219,6 @@ var ReactNativeEventEmitter = merge(ReactEventEmitterMixin, {
       );
     }
   },
-});
+};
 
 module.exports = ReactNativeEventEmitter;
diff --git a/src/renderers/native/ReactIOS/IOSDefaultEventPluginOrder.js b/src/renderers/native/ReactNativeEventPluginOrder.js
similarity index 69%
rename from src/renderers/native/ReactIOS/IOSDefaultEventPluginOrder.js
rename to src/renderers/native/ReactNativeEventPluginOrder.js
index eae211c40f..b1b5f66d11 100644
--- a/src/renderers/native/ReactIOS/IOSDefaultEventPluginOrder.js
+++ b/src/renderers/native/ReactNativeEventPluginOrder.js
@@ -6,14 +6,14 @@
  * LICENSE file in the root directory of this source tree. An additional grant
  * of patent rights can be found in the PATENTS file in the same directory.
  *
- * @providesModule IOSDefaultEventPluginOrder
+ * @providesModule ReactNativeEventPluginOrder
  * @flow
  */
 'use strict';
 
-var IOSDefaultEventPluginOrder = [
+var ReactNativeEventPluginOrder = [
   'ResponderEventPlugin',
-  'IOSNativeBridgeEventPlugin',
+  'ReactNativeBridgeEventPlugin',
 ];
 
-module.exports = IOSDefaultEventPluginOrder;
+module.exports = ReactNativeEventPluginOrder;
diff --git a/src/renderers/native/ReactNative/ReactNativeGlobalResponderHandler.js b/src/renderers/native/ReactNativeGlobalResponderHandler.js
similarity index 100%
rename from src/renderers/native/ReactNative/ReactNativeGlobalResponderHandler.js
rename to src/renderers/native/ReactNativeGlobalResponderHandler.js
diff --git a/src/renderers/native/ReactNative/ReactNativeMount.js b/src/renderers/native/ReactNativeMount.js
similarity index 87%
rename from src/renderers/native/ReactNative/ReactNativeMount.js
rename to src/renderers/native/ReactNativeMount.js
index 50d300923a..c44372d1dc 100644
--- a/src/renderers/native/ReactNative/ReactNativeMount.js
+++ b/src/renderers/native/ReactNativeMount.js
@@ -12,9 +12,9 @@
 'use strict';
 
 var ReactElement = require('ReactElement');
+var ReactInstrumentation = require('ReactInstrumentation');
 var ReactNativeContainerInfo = require('ReactNativeContainerInfo');
 var ReactNativeTagHandles = require('ReactNativeTagHandles');
-var ReactPerf = require('ReactPerf');
 var ReactReconciler = require('ReactReconciler');
 var ReactUpdateQueue = require('ReactUpdateQueue');
 var ReactUpdates = require('ReactUpdates');
@@ -138,6 +138,16 @@ var ReactNativeMount = {
     var instance = instantiateReactComponent(nextWrappedElement);
     ReactNativeMount._instancesByContainerID[containerTag] = instance;
 
+    if (__DEV__) {
+      // Mute future events from the top level wrapper.
+      // It is an implementation detail that devtools should not know about.
+      instance._debugID = 0;
+
+      if (__DEV__) {
+        ReactInstrumentation.debugTool.onBeginFlush();
+      }
+    }
+
     // The initial render is synchronous but any updates that happen during
     // rendering, in componentWillMount or componentDidMount, will be batched
     // according to the current batching strategy.
@@ -147,6 +157,13 @@ var ReactNativeMount = {
       instance,
       containerTag
     );
+    if (__DEV__) {
+      // The instance here is TopLevelWrapper so we report mount for its child.
+      ReactInstrumentation.debugTool.onMountRootComponent(
+        instance._renderedComponent._debugID
+      );
+      ReactInstrumentation.debugTool.onEndFlush();
+    }
     var component = instance.getPublicInstance();
     if (callback) {
       callback.call(component);
@@ -158,20 +175,15 @@ var ReactNativeMount = {
    * @param {View} view View tree image.
    * @param {number} containerViewID View to insert sub-view into.
    */
-  _mountImageIntoNode: ReactPerf.measure(
-    // FIXME(frantic): #4441289 Hack to avoid modifying react-tools
-    'ReactComponentBrowserEnvironment',
-    'mountImageIntoNode',
-    function(mountImage, containerID) {
-      // Since we now know that the `mountImage` has been mounted, we can
-      // mark it as such.
-      var childTag = mountImage;
-      UIManager.setChildren(
-        containerID,
-        [childTag]
-      );
-    }
-  ),
+  _mountImageIntoNode: function(mountImage, containerID) {
+    // Since we now know that the `mountImage` has been mounted, we can
+    // mark it as such.
+    var childTag = mountImage;
+    UIManager.setChildren(
+      containerID,
+      [childTag]
+    );
+  },
 
   /**
    * Standard unmounting of the component that is rendered into `containerID`,
@@ -204,8 +216,14 @@ var ReactNativeMount = {
     if (!instance) {
       return false;
     }
+    if (__DEV__) {
+      ReactInstrumentation.debugTool.onBeginFlush();
+    }
     ReactNativeMount.unmountComponentFromNode(instance, containerTag);
     delete ReactNativeMount._instancesByContainerID[containerTag];
+    if (__DEV__) {
+      ReactInstrumentation.debugTool.onEndFlush();
+    }
     return true;
   },
 
@@ -229,10 +247,4 @@ var ReactNativeMount = {
 
 };
 
-ReactNativeMount.renderComponent = ReactPerf.measure(
-  'ReactMount',
-  '_renderNewRootComponent',
-  ReactNativeMount.renderComponent
-);
-
 module.exports = ReactNativeMount;
diff --git a/src/renderers/native/ReactNative/ReactNativePropRegistry.js b/src/renderers/native/ReactNativePropRegistry.js
similarity index 100%
rename from src/renderers/native/ReactNative/ReactNativePropRegistry.js
rename to src/renderers/native/ReactNativePropRegistry.js
diff --git a/src/renderers/native/ReactNative/ReactNativeReconcileTransaction.js b/src/renderers/native/ReactNativeReconcileTransaction.js
similarity index 100%
rename from src/renderers/native/ReactNative/ReactNativeReconcileTransaction.js
rename to src/renderers/native/ReactNativeReconcileTransaction.js
diff --git a/src/renderers/native/ReactNative/ReactNativeTagHandles.js b/src/renderers/native/ReactNativeTagHandles.js
similarity index 100%
rename from src/renderers/native/ReactNative/ReactNativeTagHandles.js
rename to src/renderers/native/ReactNativeTagHandles.js
diff --git a/src/renderers/native/ReactNative/ReactNativeTextComponent.js b/src/renderers/native/ReactNativeTextComponent.js
similarity index 87%
rename from src/renderers/native/ReactNative/ReactNativeTextComponent.js
rename to src/renderers/native/ReactNativeTextComponent.js
index 3de8a82dd2..c93442c18d 100644
--- a/src/renderers/native/ReactNative/ReactNativeTextComponent.js
+++ b/src/renderers/native/ReactNativeTextComponent.js
@@ -11,6 +11,7 @@
 
 'use strict';
 
+var ReactInstrumentation = require('ReactInstrumentation');
 var ReactNativeComponentTree = require('ReactNativeComponentTree');
 var ReactNativeTagHandles = require('ReactNativeTagHandles');
 var UIManager = require('UIManager');
@@ -28,6 +29,10 @@ var ReactNativeTextComponent = function(text) {
 Object.assign(ReactNativeTextComponent.prototype, {
 
   mountComponent: function(transaction, nativeParent, nativeContainerInfo, context) {
+    if (__DEV__) {
+      ReactInstrumentation.debugTool.onSetText(this._debugID, this._stringText);
+    }
+
     // TODO: nativeParent should have this context already. Stop abusing context.
     invariant(
       context.isInAParentText,
@@ -65,6 +70,12 @@ Object.assign(ReactNativeTextComponent.prototype, {
           'RCTRawText',
           {text: this._stringText}
         );
+        if (__DEV__) {
+          ReactInstrumentation.debugTool.onSetText(
+            this._debugID,
+            nextStringText
+          );
+        }
       }
     }
   },
diff --git a/src/renderers/native/ReactNative/ReactNativeTreeTraversal.js b/src/renderers/native/ReactNativeTreeTraversal.js
similarity index 100%
rename from src/renderers/native/ReactNative/ReactNativeTreeTraversal.js
rename to src/renderers/native/ReactNativeTreeTraversal.js
diff --git a/src/renderers/native/ReactNative/__mocks__/InitializeJavaScriptAppEngine.js b/src/renderers/native/__mocks__/InitializeJavaScriptAppEngine.js
similarity index 81%
rename from src/renderers/native/ReactNative/__mocks__/InitializeJavaScriptAppEngine.js
rename to src/renderers/native/__mocks__/InitializeJavaScriptAppEngine.js
index 3f4b4fdd0f..bc540c10d2 100644
--- a/src/renderers/native/ReactNative/__mocks__/InitializeJavaScriptAppEngine.js
+++ b/src/renderers/native/__mocks__/InitializeJavaScriptAppEngine.js
@@ -11,4 +11,4 @@
 
 // Noop
 
-// TODO: Move all initialization callers back into react-native
+// TODO #10932517: Move all initialization callers back into react-native
diff --git a/src/renderers/native/ReactNative/__mocks__/RCTEventEmitter.js b/src/renderers/native/__mocks__/RCTEventEmitter.js
similarity index 79%
rename from src/renderers/native/ReactNative/__mocks__/RCTEventEmitter.js
rename to src/renderers/native/__mocks__/RCTEventEmitter.js
index 3f4b4fdd0f..d6e66ad500 100644
--- a/src/renderers/native/ReactNative/__mocks__/RCTEventEmitter.js
+++ b/src/renderers/native/__mocks__/RCTEventEmitter.js
@@ -9,6 +9,8 @@
 
 'use strict';
 
-// Noop
+var RCTEventEmitter = {
+  register: jest.fn(),
+};
 
-// TODO: Move all initialization callers back into react-native
+module.exports = RCTEventEmitter;
diff --git a/src/renderers/native/ReactNative/__mocks__/TextInputState.js b/src/renderers/native/__mocks__/TextInputState.js
similarity index 100%
rename from src/renderers/native/ReactNative/__mocks__/TextInputState.js
rename to src/renderers/native/__mocks__/TextInputState.js
diff --git a/src/renderers/native/ReactNative/__mocks__/UIManager.js b/src/renderers/native/__mocks__/UIManager.js
similarity index 67%
rename from src/renderers/native/ReactNative/__mocks__/UIManager.js
rename to src/renderers/native/__mocks__/UIManager.js
index 0c51ab6e6b..ddcba12ca0 100644
--- a/src/renderers/native/ReactNative/__mocks__/UIManager.js
+++ b/src/renderers/native/__mocks__/UIManager.js
@@ -12,10 +12,12 @@
 // Mock of the Native Hooks
 
 var RCTUIManager = {
-  createView: jest.genMockFunction(),
-  setChildren: jest.genMockFunction(),
-  manageChildren: jest.genMockFunction(),
-  updateView: jest.genMockFunction(),
+  createView: jest.fn(),
+  setChildren: jest.fn(),
+  manageChildren: jest.fn(),
+  updateView: jest.fn(),
+  removeSubviewsFromContainerWithID: jest.fn(),
+  replaceExistingNonRootView: jest.fn(),
 };
 
 module.exports = RCTUIManager;
diff --git a/src/renderers/native/ReactNative/__mocks__/deepDiffer.js b/src/renderers/native/__mocks__/deepDiffer.js
similarity index 100%
rename from src/renderers/native/ReactNative/__mocks__/deepDiffer.js
rename to src/renderers/native/__mocks__/deepDiffer.js
diff --git a/src/renderers/native/ReactNative/__mocks__/deepFreezeAndThrowOnMutationInDev.js b/src/renderers/native/__mocks__/deepFreezeAndThrowOnMutationInDev.js
similarity index 100%
rename from src/renderers/native/ReactNative/__mocks__/deepFreezeAndThrowOnMutationInDev.js
rename to src/renderers/native/__mocks__/deepFreezeAndThrowOnMutationInDev.js
diff --git a/src/renderers/native/ReactNative/__mocks__/flattenStyle.js b/src/renderers/native/__mocks__/flattenStyle.js
similarity index 100%
rename from src/renderers/native/ReactNative/__mocks__/flattenStyle.js
rename to src/renderers/native/__mocks__/flattenStyle.js
diff --git a/src/renderers/native/ReactNative/__tests__/ReactNativeAttributePayload-test.js b/src/renderers/native/__tests__/ReactNativeAttributePayload-test.js
similarity index 95%
rename from src/renderers/native/ReactNative/__tests__/ReactNativeAttributePayload-test.js
rename to src/renderers/native/__tests__/ReactNativeAttributePayload-test.js
index be65d175a2..85d4283d13 100644
--- a/src/renderers/native/ReactNative/__tests__/ReactNativeAttributePayload-test.js
+++ b/src/renderers/native/__tests__/ReactNativeAttributePayload-test.js
@@ -9,8 +9,8 @@
  */
 'use strict';
 
-jest.dontMock('ReactNativeAttributePayload');
-jest.dontMock('ReactNativePropRegistry');
+jest.unmock('ReactNativeAttributePayload');
+jest.unmock('ReactNativePropRegistry');
 // jest.dontMock('deepDiffer');
 // jest.dontMock('flattenStyle');
 
@@ -62,8 +62,8 @@ describe('ReactNativeAttributePayload', function() {
   });
 
   it('should use the diff attribute', () => {
-    var diffA = jest.genMockFunction().mockImpl((a, b) => true);
-    var diffB = jest.genMockFunction().mockImpl((a, b) => false);
+    var diffA = jest.fn((a, b) => true);
+    var diffB = jest.fn((a, b) => false);
     expect(diff(
       {a: [1], b: [3]},
       {a: [2], b: [4]},
@@ -74,8 +74,8 @@ describe('ReactNativeAttributePayload', function() {
   });
 
   it('should not use the diff attribute on addition/removal', () => {
-    var diffA = jest.genMockFunction();
-    var diffB = jest.genMockFunction();
+    var diffA = jest.fn();
+    var diffB = jest.fn();
     expect(diff(
       {a: [1]},
       {b: [2]},
diff --git a/src/renderers/native/ReactNative/__tests__/ReactNativeMount-test.js b/src/renderers/native/__tests__/ReactNativeMount-test.js
similarity index 100%
rename from src/renderers/native/ReactNative/__tests__/ReactNativeMount-test.js
rename to src/renderers/native/__tests__/ReactNativeMount-test.js
diff --git a/src/renderers/native/ReactNative/createReactNativeComponentClass.js b/src/renderers/native/createReactNativeComponentClass.js
similarity index 100%
rename from src/renderers/native/ReactNative/createReactNativeComponentClass.js
rename to src/renderers/native/createReactNativeComponentClass.js
diff --git a/src/renderers/native/ReactNative/findNodeHandle.js b/src/renderers/native/findNodeHandle.js
similarity index 100%
rename from src/renderers/native/ReactNative/findNodeHandle.js
rename to src/renderers/native/findNodeHandle.js
diff --git a/src/renderers/shared/event/__tests__/EventPluginHub-test.js b/src/renderers/shared/event/__tests__/EventPluginHub-test.js
index 5dc566c74b..b7d5843fc7 100644
--- a/src/renderers/shared/event/__tests__/EventPluginHub-test.js
+++ b/src/renderers/shared/event/__tests__/EventPluginHub-test.js
@@ -12,7 +12,7 @@
 'use strict';
 
 jest
-  .dontMock('EventPluginHub')
+  .unmock('EventPluginHub')
   .mock('isEventSupported');
 
 describe('EventPluginHub', function() {
diff --git a/src/renderers/shared/reconciler/ReactCompositeComponent.js b/src/renderers/shared/reconciler/ReactCompositeComponent.js
index d6ea8b1233..120e5900a4 100644
--- a/src/renderers/shared/reconciler/ReactCompositeComponent.js
+++ b/src/renderers/shared/reconciler/ReactCompositeComponent.js
@@ -18,7 +18,6 @@ var ReactErrorUtils = require('ReactErrorUtils');
 var ReactInstanceMap = require('ReactInstanceMap');
 var ReactInstrumentation = require('ReactInstrumentation');
 var ReactNodeTypes = require('ReactNodeTypes');
-var ReactPerf = require('ReactPerf');
 var ReactPropTypeLocations = require('ReactPropTypeLocations');
 var ReactPropTypeLocationNames = require('ReactPropTypeLocationNames');
 var ReactReconciler = require('ReactReconciler');
@@ -60,6 +59,40 @@ function warnIfInvalidElement(Component, element) {
   }
 }
 
+function invokeComponentDidMountWithTimer() {
+  var publicInstance = this._instance;
+  if (this._debugID !== 0) {
+    ReactInstrumentation.debugTool.onBeginLifeCycleTimer(
+      this._debugID,
+      'componentDidMount'
+    );
+  }
+  publicInstance.componentDidMount();
+  if (this._debugID !== 0) {
+    ReactInstrumentation.debugTool.onEndLifeCycleTimer(
+      this._debugID,
+      'componentDidMount'
+    );
+  }
+}
+
+function invokeComponentDidUpdateWithTimer(prevProps, prevState, prevContext) {
+  var publicInstance = this._instance;
+  if (this._debugID !== 0) {
+    ReactInstrumentation.debugTool.onBeginLifeCycleTimer(
+      this._debugID,
+      'componentDidUpdate'
+    );
+  }
+  publicInstance.componentDidUpdate(prevProps, prevState, prevContext);
+  if (this._debugID !== 0) {
+    ReactInstrumentation.debugTool.onEndLifeCycleTimer(
+      this._debugID,
+      'componentDidUpdate'
+    );
+  }
+}
+
 function shouldConstruct(Component) {
   return Component.prototype && Component.prototype.isReactComponent;
 }
@@ -119,6 +152,7 @@ var ReactCompositeComponentMixin = {
     this._nativeContainerInfo = null;
 
     // See ReactUpdateQueue
+    this._updateBatchNumber = null;
     this._pendingElement = null;
     this._pendingStateQueue = null;
     this._pendingReplaceState = false;
@@ -302,7 +336,11 @@ var ReactCompositeComponentMixin = {
     }
 
     if (inst.componentDidMount) {
-      transaction.getReactMountReady().enqueue(inst.componentDidMount, inst);
+      if (__DEV__) {
+        transaction.getReactMountReady().enqueue(invokeComponentDidMountWithTimer, this);
+      } else {
+        transaction.getReactMountReady().enqueue(inst.componentDidMount, inst);
+      }
     }
 
     return markup;
@@ -323,11 +361,47 @@ var ReactCompositeComponentMixin = {
 
   _constructComponentWithoutOwner: function(publicProps, publicContext) {
     var Component = this._currentElement.type;
+    var instanceOrElement;
     if (shouldConstruct(Component)) {
-      return new Component(publicProps, publicContext, ReactUpdateQueue);
+      if (__DEV__) {
+        if (this._debugID !== 0) {
+          ReactInstrumentation.debugTool.onBeginLifeCycleTimer(
+            this._debugID,
+            'ctor'
+          );
+        }
+      }
+      instanceOrElement = new Component(publicProps, publicContext, ReactUpdateQueue);
+      if (__DEV__) {
+        if (this._debugID !== 0) {
+          ReactInstrumentation.debugTool.onEndLifeCycleTimer(
+            this._debugID,
+            'ctor'
+          );
+        }
+      }
     } else {
-      return Component(publicProps, publicContext, ReactUpdateQueue);
+      // This can still be an instance in case of factory components
+      // but we'll count this as time spent rendering as the more common case.
+      if (__DEV__) {
+        if (this._debugID !== 0) {
+          ReactInstrumentation.debugTool.onBeginLifeCycleTimer(
+            this._debugID,
+            'render'
+          );
+        }
+      }
+      instanceOrElement = Component(publicProps, publicContext, ReactUpdateQueue);
+      if (__DEV__) {
+        if (this._debugID !== 0) {
+          ReactInstrumentation.debugTool.onEndLifeCycleTimer(
+            this._debugID,
+            'render'
+          );
+        }
+      }
     }
+    return instanceOrElement;
   },
 
   performInitialMountWithErrorHandling: function(
@@ -363,7 +437,23 @@ var ReactCompositeComponentMixin = {
   performInitialMount: function(renderedElement, nativeParent, nativeContainerInfo, transaction, context) {
     var inst = this._instance;
     if (inst.componentWillMount) {
+      if (__DEV__) {
+        if (this._debugID !== 0) {
+          ReactInstrumentation.debugTool.onBeginLifeCycleTimer(
+            this._debugID,
+            'componentWillMount'
+          );
+        }
+      }
       inst.componentWillMount();
+      if (__DEV__) {
+        if (this._debugID !== 0) {
+          ReactInstrumentation.debugTool.onEndLifeCycleTimer(
+            this._debugID,
+            'componentWillMount'
+          );
+        }
+      }
       // When mounting, calls to `setState` by `componentWillMount` will set
       // `this._pendingStateQueue` without triggering a re-render.
       if (this._pendingStateQueue) {
@@ -389,6 +479,17 @@ var ReactCompositeComponentMixin = {
       this._processChildContext(context)
     );
 
+    if (__DEV__) {
+      if (this._debugID !== 0) {
+        ReactInstrumentation.debugTool.onSetChildren(
+          this._debugID,
+          this._renderedComponent._debugID !== 0 ?
+            [this._renderedComponent._debugID] :
+            []
+        );
+      }
+    }
+
     return markup;
   },
 
@@ -410,12 +511,28 @@ var ReactCompositeComponentMixin = {
 
     if (inst.componentWillUnmount && !inst._calledComponentWillUnmount) {
       inst._calledComponentWillUnmount = true;
+      if (__DEV__) {
+        if (this._debugID !== 0) {
+          ReactInstrumentation.debugTool.onBeginLifeCycleTimer(
+            this._debugID,
+            'componentWillUnmount'
+          );
+        }
+      }
       if (safely) {
         var name = this.getName() + '.componentWillUnmount()';
         ReactErrorUtils.invokeGuardedCallback(name, inst.componentWillUnmount.bind(inst));
       } else {
         inst.componentWillUnmount();
       }
+      if (__DEV__) {
+        if (this._debugID !== 0) {
+          ReactInstrumentation.debugTool.onEndLifeCycleTimer(
+            this._debugID,
+            'componentWillUnmount'
+          );
+        }
+      }
     }
 
     if (this._renderedComponent) {
@@ -648,9 +765,7 @@ var ReactCompositeComponentMixin = {
         transaction,
         this._context
       );
-    }
-
-    if (this._pendingStateQueue !== null || this._pendingForceUpdate) {
+    } else if (this._pendingStateQueue !== null || this._pendingForceUpdate) {
       this.updateComponent(
         transaction,
         this._currentElement,
@@ -658,6 +773,8 @@ var ReactCompositeComponentMixin = {
         this._context,
         this._context
       );
+    } else {
+      this._updateBatchNumber = null;
     }
   },
 
@@ -710,15 +827,47 @@ var ReactCompositeComponentMixin = {
     // _pendingStateQueue which will ensure that any state updates gets
     // immediately reconciled instead of waiting for the next batch.
     if (willReceive && inst.componentWillReceiveProps) {
+      if (__DEV__) {
+        if (this._debugID !== 0) {
+          ReactInstrumentation.debugTool.onBeginLifeCycleTimer(
+            this._debugID,
+            'componentWillReceiveProps'
+          );
+        }
+      }
       inst.componentWillReceiveProps(nextProps, nextContext);
+      if (__DEV__) {
+        if (this._debugID !== 0) {
+          ReactInstrumentation.debugTool.onEndLifeCycleTimer(
+            this._debugID,
+            'componentWillReceiveProps'
+          );
+        }
+      }
     }
 
     var nextState = this._processPendingState(nextProps, nextContext);
+    var shouldUpdate = true;
 
-    var shouldUpdate =
-      this._pendingForceUpdate ||
-      !inst.shouldComponentUpdate ||
-      inst.shouldComponentUpdate(nextProps, nextState, nextContext);
+    if (!this._pendingForceUpdate && inst.shouldComponentUpdate) {
+      if (__DEV__) {
+        if (this._debugID !== 0) {
+          ReactInstrumentation.debugTool.onBeginLifeCycleTimer(
+            this._debugID,
+            'shouldComponentUpdate'
+          );
+        }
+      }
+      shouldUpdate = inst.shouldComponentUpdate(nextProps, nextState, nextContext);
+      if (__DEV__) {
+        if (this._debugID !== 0) {
+          ReactInstrumentation.debugTool.onEndLifeCycleTimer(
+            this._debugID,
+            'shouldComponentUpdate'
+          );
+        }
+      }
+    }
 
     if (__DEV__) {
       warning(
@@ -729,6 +878,7 @@ var ReactCompositeComponentMixin = {
       );
     }
 
+    this._updateBatchNumber = null;
     if (shouldUpdate) {
       this._pendingForceUpdate = false;
       // Will set `this.props`, `this.state` and `this.context`.
@@ -813,7 +963,23 @@ var ReactCompositeComponentMixin = {
     }
 
     if (inst.componentWillUpdate) {
+      if (__DEV__) {
+        if (this._debugID !== 0) {
+          ReactInstrumentation.debugTool.onBeginLifeCycleTimer(
+            this._debugID,
+            'componentWillUpdate'
+          );
+        }
+      }
       inst.componentWillUpdate(nextProps, nextState, nextContext);
+      if (__DEV__) {
+        if (this._debugID !== 0) {
+          ReactInstrumentation.debugTool.onEndLifeCycleTimer(
+            this._debugID,
+            'componentWillUpdate'
+          );
+        }
+      }
     }
 
     this._currentElement = nextElement;
@@ -825,10 +991,17 @@ var ReactCompositeComponentMixin = {
     this._updateRenderedComponent(transaction, unmaskedContext);
 
     if (hasComponentDidUpdate) {
-      transaction.getReactMountReady().enqueue(
-        inst.componentDidUpdate.bind(inst, prevProps, prevState, prevContext),
-        inst
-      );
+      if (__DEV__) {
+        transaction.getReactMountReady().enqueue(
+          invokeComponentDidUpdateWithTimer.bind(this, prevProps, prevState, prevContext),
+          this
+        );
+      } else {
+        transaction.getReactMountReady().enqueue(
+          inst.componentDidUpdate.bind(inst, prevProps, prevState, prevContext),
+          inst
+        );
+      }
     }
   },
 
@@ -857,6 +1030,7 @@ var ReactCompositeComponentMixin = {
       this._renderedComponent = this._instantiateReactComponent(
         nextRenderedElement
       );
+
       var nextMarkup = ReactReconciler.mountComponent(
         this._renderedComponent,
         transaction,
@@ -864,7 +1038,23 @@ var ReactCompositeComponentMixin = {
         this._nativeContainerInfo,
         this._processChildContext(context)
       );
-      this._replaceNodeWithMarkup(oldNativeNode, nextMarkup);
+
+      if (__DEV__) {
+        if (this._debugID !== 0) {
+          ReactInstrumentation.debugTool.onSetChildren(
+            this._debugID,
+            this._renderedComponent._debugID !== 0 ?
+              [this._renderedComponent._debugID] :
+              []
+          );
+        }
+      }
+
+      this._replaceNodeWithMarkup(
+        oldNativeNode,
+        nextMarkup,
+        prevComponentInstance
+      );
     }
   },
 
@@ -873,10 +1063,11 @@ var ReactCompositeComponentMixin = {
    *
    * @protected
    */
-  _replaceNodeWithMarkup: function(oldNativeNode, nextMarkup) {
+  _replaceNodeWithMarkup: function(oldNativeNode, nextMarkup, prevInstance) {
     ReactComponentEnvironment.replaceNodeWithMarkup(
       oldNativeNode,
-      nextMarkup
+      nextMarkup,
+      prevInstance
     );
   },
 
@@ -885,7 +1076,25 @@ var ReactCompositeComponentMixin = {
    */
   _renderValidatedComponentWithoutOwnerOrContext: function() {
     var inst = this._instance;
+
+    if (__DEV__) {
+      if (this._debugID !== 0) {
+        ReactInstrumentation.debugTool.onBeginLifeCycleTimer(
+          this._debugID,
+          'render'
+        );
+      }
+    }
     var renderedComponent = inst.render();
+    if (__DEV__) {
+      if (this._debugID !== 0) {
+        ReactInstrumentation.debugTool.onEndLifeCycleTimer(
+          this._debugID,
+          'render'
+        );
+      }
+    }
+
     if (__DEV__) {
       // We allow auto-mocks to proceed as if they're returning null.
       if (renderedComponent === undefined &&
@@ -919,6 +1128,7 @@ var ReactCompositeComponentMixin = {
         'returned undefined, an array or some other invalid object.',
       this.getName() || 'ReactCompositeComponent'
     );
+
     return renderedComponent;
   },
 
@@ -999,16 +1209,6 @@ var ReactCompositeComponentMixin = {
 
 };
 
-ReactPerf.measureMethods(
-  ReactCompositeComponentMixin,
-  'ReactCompositeComponent',
-  {
-    mountComponent: 'mountComponent',
-    updateComponent: 'updateComponent',
-    _renderValidatedComponent: '_renderValidatedComponent',
-  }
-);
-
 var ReactCompositeComponent = {
 
   Mixin: ReactCompositeComponentMixin,
diff --git a/src/renderers/shared/reconciler/ReactMultiChild.js b/src/renderers/shared/reconciler/ReactMultiChild.js
index 66f3861321..474ddc63dc 100644
--- a/src/renderers/shared/reconciler/ReactMultiChild.js
+++ b/src/renderers/shared/reconciler/ReactMultiChild.js
@@ -12,12 +12,14 @@
 'use strict';
 
 var ReactComponentEnvironment = require('ReactComponentEnvironment');
+var ReactInstrumentation = require('ReactInstrumentation');
 var ReactMultiChildUpdateTypes = require('ReactMultiChildUpdateTypes');
 
 var ReactCurrentOwner = require('ReactCurrentOwner');
 var ReactReconciler = require('ReactReconciler');
 var ReactChildReconciler = require('ReactChildReconciler');
 
+var emptyFunction = require('emptyFunction');
 var flattenChildren = require('flattenChildren');
 var invariant = require('invariant');
 
@@ -137,6 +139,16 @@ function processQueue(inst, updateQueue) {
   );
 }
 
+var setChildrenForInstrumentation = emptyFunction;
+if (__DEV__) {
+  setChildrenForInstrumentation = function(children) {
+    ReactInstrumentation.debugTool.onSetChildren(
+      this._debugID,
+      children ? Object.keys(children).map(key => children[key]._debugID) : []
+    );
+  };
+}
+
 /**
  * ReactMultiChild are capable of reconciling multiple children.
  *
@@ -214,6 +226,7 @@ var ReactMultiChild = {
         nestedChildren, transaction, context
       );
       this._renderedChildren = children;
+
       var mountImages = [];
       var index = 0;
       for (var name in children) {
@@ -230,6 +243,11 @@ var ReactMultiChild = {
           mountImages.push(mountImage);
         }
       }
+
+      if (__DEV__) {
+        setChildrenForInstrumentation.call(this, children);
+      }
+
       return mountImages;
     },
 
@@ -357,6 +375,10 @@ var ReactMultiChild = {
         processQueue(this, updates);
       }
       this._renderedChildren = nextChildren;
+
+      if (__DEV__) {
+        setChildrenForInstrumentation.call(this, nextChildren);
+      }
     },
 
     /**
diff --git a/src/renderers/shared/reconciler/ReactReconciler.js b/src/renderers/shared/reconciler/ReactReconciler.js
index ae7806e4fc..cf2bfad093 100644
--- a/src/renderers/shared/reconciler/ReactReconciler.js
+++ b/src/renderers/shared/reconciler/ReactReconciler.js
@@ -14,6 +14,8 @@
 var ReactRef = require('ReactRef');
 var ReactInstrumentation = require('ReactInstrumentation');
 
+var invariant = require('invariant');
+
 /**
  * Helper to call ReactRef.attachRefs with this composite component, split out
  * to avoid allocations in the transaction mount-ready queue.
@@ -42,6 +44,14 @@ var ReactReconciler = {
     nativeContainerInfo,
     context
   ) {
+    if (__DEV__) {
+      if (internalInstance._debugID !== 0) {
+        ReactInstrumentation.debugTool.onBeginReconcilerTimer(
+          internalInstance._debugID,
+          'mountComponent'
+        );
+      }
+    }
     var markup = internalInstance.mountComponent(
       transaction,
       nativeParent,
@@ -53,7 +63,15 @@ var ReactReconciler = {
       transaction.getReactMountReady().enqueue(attachRefs, internalInstance);
     }
     if (__DEV__) {
-      ReactInstrumentation.debugTool.onMountComponent(internalInstance);
+      if (internalInstance._debugID !== 0) {
+        ReactInstrumentation.debugTool.onEndReconcilerTimer(
+          internalInstance._debugID,
+          'mountComponent'
+        );
+        ReactInstrumentation.debugTool.onMountComponent(
+          internalInstance._debugID
+        );
+      }
     }
     return markup;
   },
@@ -73,10 +91,26 @@ var ReactReconciler = {
    * @internal
    */
   unmountComponent: function(internalInstance, safely) {
+    if (__DEV__) {
+      if (internalInstance._debugID !== 0) {
+        ReactInstrumentation.debugTool.onBeginReconcilerTimer(
+          internalInstance._debugID,
+          'unmountComponent'
+        );
+      }
+    }
     ReactRef.detachRefs(internalInstance, internalInstance._currentElement);
     internalInstance.unmountComponent(safely);
     if (__DEV__) {
-      ReactInstrumentation.debugTool.onUnmountComponent(internalInstance);
+      if (internalInstance._debugID !== 0) {
+        ReactInstrumentation.debugTool.onEndReconcilerTimer(
+          internalInstance._debugID,
+          'unmountComponent'
+        );
+        ReactInstrumentation.debugTool.onUnmountComponent(
+          internalInstance._debugID
+        );
+      }
     }
   },
 
@@ -110,6 +144,15 @@ var ReactReconciler = {
       return;
     }
 
+    if (__DEV__) {
+      if (internalInstance._debugID !== 0) {
+        ReactInstrumentation.debugTool.onBeginReconcilerTimer(
+          internalInstance._debugID,
+          'receiveComponent'
+        );
+      }
+    }
+
     var refsChanged = ReactRef.shouldUpdateRefs(
       prevElement,
       nextElement
@@ -128,7 +171,15 @@ var ReactReconciler = {
     }
 
     if (__DEV__) {
-      ReactInstrumentation.debugTool.onUpdateComponent(internalInstance);
+      if (internalInstance._debugID !== 0) {
+        ReactInstrumentation.debugTool.onEndReconcilerTimer(
+          internalInstance._debugID,
+          'receiveComponent'
+        );
+        ReactInstrumentation.debugTool.onUpdateComponent(
+          internalInstance._debugID
+        );
+      }
     }
   },
 
@@ -141,11 +192,41 @@ var ReactReconciler = {
    */
   performUpdateIfNecessary: function(
     internalInstance,
-    transaction
+    transaction,
+    updateBatchNumber
   ) {
+    if (internalInstance._updateBatchNumber !== updateBatchNumber) {
+      // The component's enqueued batch number should always be the current
+      // batch or the following one.
+      invariant(
+        internalInstance._updateBatchNumber == null ||
+        internalInstance._updateBatchNumber === updateBatchNumber + 1,
+        'performUpdateIfNecessary: Unexpected batch number (current %s, ' +
+        'pending %s)',
+        updateBatchNumber,
+        internalInstance._updateBatchNumber
+      );
+      return;
+    }
+    if (__DEV__) {
+      if (internalInstance._debugID !== 0) {
+        ReactInstrumentation.debugTool.onBeginReconcilerTimer(
+          internalInstance._debugID,
+          'performUpdateIfNecessary'
+        );
+      }
+    }
     internalInstance.performUpdateIfNecessary(transaction);
     if (__DEV__) {
-      ReactInstrumentation.debugTool.onUpdateComponent(internalInstance);
+      if (internalInstance._debugID !== 0) {
+        ReactInstrumentation.debugTool.onEndReconcilerTimer(
+          internalInstance._debugID,
+          'performUpdateIfNecessary'
+        );
+        ReactInstrumentation.debugTool.onUpdateComponent(
+          internalInstance._debugID
+        );
+      }
     }
   },
 
diff --git a/src/renderers/shared/reconciler/ReactUpdates.js b/src/renderers/shared/reconciler/ReactUpdates.js
index 6fd1d2f3b5..d8471372b7 100644
--- a/src/renderers/shared/reconciler/ReactUpdates.js
+++ b/src/renderers/shared/reconciler/ReactUpdates.js
@@ -14,13 +14,14 @@
 var CallbackQueue = require('CallbackQueue');
 var PooledClass = require('PooledClass');
 var ReactFeatureFlags = require('ReactFeatureFlags');
-var ReactPerf = require('ReactPerf');
+var ReactInstrumentation = require('ReactInstrumentation');
 var ReactReconciler = require('ReactReconciler');
 var Transaction = require('Transaction');
 
 var invariant = require('invariant');
 
 var dirtyComponents = [];
+var updateBatchNumber = 0;
 var asapCallbackQueue = CallbackQueue.getPooled();
 var asapEnqueued = false;
 
@@ -137,6 +138,13 @@ function runBatchedUpdates(transaction) {
   // them before their children by sorting the array.
   dirtyComponents.sort(mountOrderComparator);
 
+  // Any updates enqueued while reconciling must be performed after this entire
+  // batch. Otherwise, if dirtyComponents is [A, B] where A has children B and
+  // C, B could update twice in a single batch if C's render enqueues an update
+  // to B (since B would have already updated, we should skip it, and the only
+  // way we can know to do so is by checking the batch counter).
+  updateBatchNumber++;
+
   for (var i = 0; i < len; i++) {
     // If a component is unmounted before pending changes apply, it will still
     // be here, but we assume that it has cleared its _pendingCallbacks and
@@ -165,7 +173,8 @@ function runBatchedUpdates(transaction) {
 
     ReactReconciler.performUpdateIfNecessary(
       component,
-      transaction.reconcileTransaction
+      transaction.reconcileTransaction,
+      updateBatchNumber
     );
 
     if (markerName) {
@@ -184,6 +193,10 @@ function runBatchedUpdates(transaction) {
 }
 
 var flushBatchedUpdates = function() {
+  if (__DEV__) {
+    ReactInstrumentation.debugTool.onBeginFlush();
+  }
+
   // ReactUpdatesFlushTransaction's wrappers will clear the dirtyComponents
   // array and perform any updates enqueued by mount-ready handlers (i.e.,
   // componentDidUpdate) but we need to check here too in order to catch
@@ -203,12 +216,11 @@ var flushBatchedUpdates = function() {
       CallbackQueue.release(queue);
     }
   }
+
+  if (__DEV__) {
+    ReactInstrumentation.debugTool.onEndFlush();
+  }
 };
-flushBatchedUpdates = ReactPerf.measure(
-  'ReactUpdates',
-  'flushBatchedUpdates',
-  flushBatchedUpdates
-);
 
 /**
  * Mark a component as needing a rerender, adding an optional callback to a
@@ -229,6 +241,9 @@ function enqueueUpdate(component) {
   }
 
   dirtyComponents.push(component);
+  if (component._updateBatchNumber == null) {
+    component._updateBatchNumber = updateBatchNumber + 1;
+  }
 }
 
 /**
diff --git a/src/renderers/shared/reconciler/__tests__/ReactComponent-test.js b/src/renderers/shared/reconciler/__tests__/ReactComponent-test.js
index 444bedddb8..370931595d 100644
--- a/src/renderers/shared/reconciler/__tests__/ReactComponent-test.js
+++ b/src/renderers/shared/reconciler/__tests__/ReactComponent-test.js
@@ -255,7 +255,7 @@ describe('ReactComponent', function() {
   });
 
   it('fires the callback after a component is rendered', function() {
-    var callback = jest.genMockFn();
+    var callback = jest.fn();
     var container = document.createElement('div');
     ReactDOM.render(<div />, container, callback);
     expect(callback.mock.calls.length).toBe(1);
diff --git a/src/renderers/shared/reconciler/__tests__/ReactCompositeComponentNestedState-test.js b/src/renderers/shared/reconciler/__tests__/ReactCompositeComponentNestedState-test.js
index d574d57b9a..353892ee98 100644
--- a/src/renderers/shared/reconciler/__tests__/ReactCompositeComponentNestedState-test.js
+++ b/src/renderers/shared/reconciler/__tests__/ReactCompositeComponentNestedState-test.js
@@ -90,7 +90,7 @@ describe('ReactCompositeComponentNestedState-state', function() {
     var container = document.createElement('div');
     document.body.appendChild(container);
 
-    var logger = jest.genMockFn();
+    var logger = jest.fn();
 
     void ReactDOM.render(
       <ParentComponent logger={logger} />,
diff --git a/src/renderers/shared/reconciler/__tests__/ReactCompositeComponentState-test.js b/src/renderers/shared/reconciler/__tests__/ReactCompositeComponentState-test.js
index 49045338dc..f043381a5c 100644
--- a/src/renderers/shared/reconciler/__tests__/ReactCompositeComponentState-test.js
+++ b/src/renderers/shared/reconciler/__tests__/ReactCompositeComponentState-test.js
@@ -130,7 +130,7 @@ describe('ReactCompositeComponent-state', function() {
     var container = document.createElement('div');
     document.body.appendChild(container);
 
-    var stateListener = jest.genMockFn();
+    var stateListener = jest.fn();
     var instance = ReactDOM.render(
       <TestComponent stateListener={stateListener} />,
       container,
diff --git a/src/renderers/shared/reconciler/__tests__/ReactMultiChild-test.js b/src/renderers/shared/reconciler/__tests__/ReactMultiChild-test.js
index 979b2115ad..079eec06d5 100644
--- a/src/renderers/shared/reconciler/__tests__/ReactMultiChild-test.js
+++ b/src/renderers/shared/reconciler/__tests__/ReactMultiChild-test.js
@@ -26,9 +26,9 @@ describe('ReactMultiChild', function() {
     it('should update children when possible', function() {
       var container = document.createElement('div');
 
-      var mockMount = jest.genMockFn();
-      var mockUpdate = jest.genMockFn();
-      var mockUnmount = jest.genMockFn();
+      var mockMount = jest.fn();
+      var mockUpdate = jest.fn();
+      var mockUnmount = jest.fn();
 
       var MockComponent = React.createClass({
         componentDidMount: mockMount,
@@ -59,8 +59,8 @@ describe('ReactMultiChild', function() {
     it('should replace children with different constructors', function() {
       var container = document.createElement('div');
 
-      var mockMount = jest.genMockFn();
-      var mockUnmount = jest.genMockFn();
+      var mockMount = jest.fn();
+      var mockUnmount = jest.fn();
 
       var MockComponent = React.createClass({
         componentDidMount: mockMount,
@@ -87,8 +87,8 @@ describe('ReactMultiChild', function() {
     it('should NOT replace children with different owners', function() {
       var container = document.createElement('div');
 
-      var mockMount = jest.genMockFn();
-      var mockUnmount = jest.genMockFn();
+      var mockMount = jest.fn();
+      var mockUnmount = jest.fn();
 
       var MockComponent = React.createClass({
         componentDidMount: mockMount,
@@ -124,8 +124,8 @@ describe('ReactMultiChild', function() {
     it('should replace children with different keys', function() {
       var container = document.createElement('div');
 
-      var mockMount = jest.genMockFn();
-      var mockUnmount = jest.genMockFn();
+      var mockMount = jest.fn();
+      var mockUnmount = jest.fn();
 
       var MockComponent = React.createClass({
         componentDidMount: mockMount,
diff --git a/src/renderers/shared/reconciler/__tests__/ReactUpdates-test.js b/src/renderers/shared/reconciler/__tests__/ReactUpdates-test.js
index f59193d691..96ff9d1835 100644
--- a/src/renderers/shared/reconciler/__tests__/ReactUpdates-test.js
+++ b/src/renderers/shared/reconciler/__tests__/ReactUpdates-test.js
@@ -1024,4 +1024,102 @@ describe('ReactUpdates', function() {
       'to be a function. Instead received: Foo (keys: a, b).'
     );
   });
+
+  it('does not update one component twice in a batch (#2410)', function() {
+    var Parent = React.createClass({
+      getChild: function() {
+        return this.refs.child;
+      },
+      render: function() {
+        return <Child ref="child" />;
+      },
+    });
+
+    var renderCount = 0;
+    var postRenderCount = 0;
+    var once = false;
+    var Child = React.createClass({
+      getInitialState: function() {
+        return {updated: false};
+      },
+      componentWillUpdate: function() {
+        if (!once) {
+          once = true;
+          this.setState({updated: true});
+        }
+      },
+      componentDidMount: function() {
+        expect(renderCount).toBe(postRenderCount + 1);
+        postRenderCount++;
+      },
+      componentDidUpdate: function() {
+        expect(renderCount).toBe(postRenderCount + 1);
+        postRenderCount++;
+      },
+      render: function() {
+        expect(renderCount).toBe(postRenderCount);
+        renderCount++;
+        return <div />;
+      },
+    });
+
+    var parent = ReactTestUtils.renderIntoDocument(<Parent />);
+    var child = parent.getChild();
+    ReactDOM.unstable_batchedUpdates(function() {
+      parent.forceUpdate();
+      child.forceUpdate();
+    });
+  });
+
+  it('does not update one component twice in a batch (#6371)', function() {
+    var callbacks = [];
+    function emitChange() {
+      callbacks.forEach(c => c());
+    }
+
+    class App extends React.Component {
+      constructor(props) {
+        super(props);
+        this.state = { showChild: true };
+      }
+      componentDidMount() {
+        console.log('about to remove child via set state');
+        this.setState({ showChild: false });
+      }
+      render() {
+        return (
+          <div>
+            <ForceUpdatesOnChange />
+            {this.state.showChild && <EmitsChangeOnUnmount />}
+          </div>
+        );
+      }
+    }
+
+    class EmitsChangeOnUnmount extends React.Component {
+      componentWillUnmount() {
+        emitChange();
+      }
+      render() {
+        return null;
+      }
+    }
+
+    class ForceUpdatesOnChange extends React.Component {
+      componentDidMount() {
+        this.onChange = () => this.forceUpdate();
+        this.onChange();
+        callbacks.push(this.onChange);
+      }
+      componentWillUnmount() {
+        callbacks = callbacks.filter((c) => c !== this.onChange);
+      }
+      render() {
+        return <div key={Math.random()} onClick={function() {}} />;
+      }
+    }
+
+    ReactDOM.render(<App />, document.createElement('div'));
+  });
+
 });
diff --git a/src/renderers/shared/reconciler/instantiateReactComponent.js b/src/renderers/shared/reconciler/instantiateReactComponent.js
index 796e037b99..326e931a13 100644
--- a/src/renderers/shared/reconciler/instantiateReactComponent.js
+++ b/src/renderers/shared/reconciler/instantiateReactComponent.js
@@ -14,6 +14,7 @@
 var ReactCompositeComponent = require('ReactCompositeComponent');
 var ReactEmptyComponent = require('ReactEmptyComponent');
 var ReactNativeComponent = require('ReactNativeComponent');
+var ReactInstrumentation = require('ReactInstrumentation');
 
 var invariant = require('invariant');
 var warning = require('warning');
@@ -40,6 +41,21 @@ function getDeclarationErrorAddendum(owner) {
   return '';
 }
 
+function getDisplayName(instance) {
+  var element = instance._currentElement;
+  if (element == null) {
+    return '#empty';
+  } else if (typeof element === 'string' || typeof element === 'number') {
+    return '#text';
+  } else if (typeof element.type === 'string') {
+    return element.type;
+  } else if (instance.getName) {
+    return instance.getName() || 'Unknown';
+  } else {
+    return element.type.displayName || element.type.name || 'Unknown';
+  }
+}
+
 /**
  * Check if the type reference is a known internal type. I.e. not a user
  * provided composite type.
@@ -56,6 +72,8 @@ function isInternalComponentType(type) {
   );
 }
 
+var nextDebugID = 1;
+
 /**
  * Given a ReactNode, create an instance that will actually be mounted.
  *
@@ -66,7 +84,8 @@ function isInternalComponentType(type) {
 function instantiateReactComponent(node) {
   var instance;
 
-  if (node === null || node === false) {
+  var isEmpty = node === null || node === false;
+  if (isEmpty) {
     instance = ReactEmptyComponent.create(instantiateReactComponent);
   } else if (typeof node === 'object') {
     var element = node;
@@ -121,6 +140,20 @@ function instantiateReactComponent(node) {
     instance._warnedAboutRefsInRender = false;
   }
 
+  if (__DEV__) {
+    var debugID = isEmpty ? 0 : nextDebugID++;
+    instance._debugID = debugID;
+
+    if (debugID !== 0) {
+      var displayName = getDisplayName(instance);
+      ReactInstrumentation.debugTool.onSetDisplayName(debugID, displayName);
+      var owner = node && node._owner;
+      if (owner) {
+        ReactInstrumentation.debugTool.onSetOwner(debugID, owner._debugID);
+      }
+    }
+  }
+
   // Internal instances should fully constructed at this point, so they should
   // not get any new fields added to them at this point.
   if (__DEV__) {
diff --git a/src/shared/utils/__tests__/accumulateInto-test.js b/src/shared/utils/__tests__/accumulateInto-test.js
index 8dd9ee6f14..d12f572555 100644
--- a/src/shared/utils/__tests__/accumulateInto-test.js
+++ b/src/shared/utils/__tests__/accumulateInto-test.js
@@ -12,7 +12,7 @@
 'use strict';
 
 jest
-  .dontMock('accumulateInto');
+  .unmock('accumulateInto');
 
 var accumulateInto;
 
diff --git a/src/test/ReactDefaultPerf.js b/src/test/ReactDefaultPerf.js
deleted file mode 100644
index 5cb43e9048..0000000000
--- a/src/test/ReactDefaultPerf.js
+++ /dev/null
@@ -1,361 +0,0 @@
-/**
- * Copyright 2013-present, Facebook, Inc.
- * All rights reserved.
- *
- * This source code is licensed under the BSD-style license found in the
- * LICENSE file in the root directory of this source tree. An additional grant
- * of patent rights can be found in the PATENTS file in the same directory.
- *
- * @providesModule ReactDefaultPerf
- */
-
-'use strict';
-
-var DOMProperty = require('DOMProperty');
-var ReactDOMComponentTree = require('ReactDOMComponentTree');
-var ReactDefaultPerfAnalysis = require('ReactDefaultPerfAnalysis');
-var ReactMount = require('ReactMount');
-var ReactPerf = require('ReactPerf');
-
-var performanceNow = require('performanceNow');
-var warning = require('warning');
-
-function roundFloat(val) {
-  return Math.floor(val * 100) / 100;
-}
-
-function addValue(obj, key, val) {
-  obj[key] = (obj[key] || 0) + val;
-}
-
-// Composite/text components don't have any built-in ID: we have to make our own
-var compositeIDMap;
-var compositeIDCounter = 17000;
-function getIDOfComposite(inst) {
-  if (!compositeIDMap) {
-    compositeIDMap = new WeakMap();
-  }
-  if (compositeIDMap.has(inst)) {
-    return compositeIDMap.get(inst);
-  } else {
-    var id = compositeIDCounter++;
-    compositeIDMap.set(inst, id);
-    return id;
-  }
-}
-
-function getID(inst) {
-  if (inst.hasOwnProperty('_rootNodeID')) {
-    return inst._rootNodeID;
-  } else {
-    return getIDOfComposite(inst);
-  }
-}
-
-function stripComplexValues(key, value) {
-  if (typeof value !== 'object' || Array.isArray(value) || value == null) {
-    return value;
-  }
-  var prototype = Object.getPrototypeOf(value);
-  if (!prototype || prototype === Object.prototype) {
-    return value;
-  }
-  return '<not serializable>';
-}
-
-// This implementation of ReactPerf is going away some time mid 15.x.
-// While we plan to keep most of the API, the actual format of measurements
-// will change dramatically. To signal this, we wrap them into an opaque-ish
-// object to discourage reaching into it until the API stabilizes.
-function wrapLegacyMeasurements(measurements) {
-  return { __unstable_this_format_will_change: measurements };
-}
-function unwrapLegacyMeasurements(measurements) {
-  return measurements && measurements.__unstable_this_format_will_change || measurements;
-}
-
-var warnedAboutPrintDOM = false;
-var warnedAboutGetMeasurementsSummaryMap = false;
-
-var ReactDefaultPerf = {
-  _allMeasurements: [], // last item in the list is the current one
-  _mountStack: [0],
-  _compositeStack: [],
-  _injected: false,
-
-  start: function() {
-    if (!ReactDefaultPerf._injected) {
-      ReactPerf.injection.injectMeasure(ReactDefaultPerf.measure);
-    }
-
-    ReactDefaultPerf._allMeasurements.length = 0;
-    ReactPerf.enableMeasure = true;
-  },
-
-  stop: function() {
-    ReactPerf.enableMeasure = false;
-  },
-
-  getLastMeasurements: function() {
-    return wrapLegacyMeasurements(ReactDefaultPerf._allMeasurements);
-  },
-
-  printExclusive: function(measurements) {
-    measurements = unwrapLegacyMeasurements(measurements || ReactDefaultPerf._allMeasurements);
-    var summary = ReactDefaultPerfAnalysis.getExclusiveSummary(measurements);
-    console.table(summary.map(function(item) {
-      return {
-        'Component class name': item.componentName,
-        'Total inclusive time (ms)': roundFloat(item.inclusive),
-        'Exclusive mount time (ms)': roundFloat(item.exclusive),
-        'Exclusive render time (ms)': roundFloat(item.render),
-        'Mount time per instance (ms)': roundFloat(item.exclusive / item.count),
-        'Render time per instance (ms)': roundFloat(item.render / item.count),
-        'Instances': item.count,
-      };
-    }));
-    // TODO: ReactDefaultPerfAnalysis.getTotalTime() does not return the correct
-    // number.
-  },
-
-  printInclusive: function(measurements) {
-    measurements = unwrapLegacyMeasurements(measurements || ReactDefaultPerf._allMeasurements);
-    var summary = ReactDefaultPerfAnalysis.getInclusiveSummary(measurements);
-    console.table(summary.map(function(item) {
-      return {
-        'Owner > component': item.componentName,
-        'Inclusive time (ms)': roundFloat(item.time),
-        'Instances': item.count,
-      };
-    }));
-    console.log(
-      'Total time:',
-      ReactDefaultPerfAnalysis.getTotalTime(measurements).toFixed(2) + ' ms'
-    );
-  },
-
-  getMeasurementsSummaryMap: function(measurements) {
-    warning(
-      warnedAboutGetMeasurementsSummaryMap,
-      '`ReactPerf.getMeasurementsSummaryMap(...)` is deprecated. Use ' +
-      '`ReactPerf.getWasted(...)` instead.'
-    );
-    warnedAboutGetMeasurementsSummaryMap = true;
-    return ReactDefaultPerf.getWasted(measurements);
-  },
-
-  getWasted: function(measurements) {
-    measurements = unwrapLegacyMeasurements(measurements);
-    var summary = ReactDefaultPerfAnalysis.getInclusiveSummary(
-      measurements,
-      true
-    );
-    return summary.map(function(item) {
-      return {
-        'Owner > component': item.componentName,
-        'Wasted time (ms)': item.time,
-        'Instances': item.count,
-      };
-    });
-  },
-
-  printWasted: function(measurements) {
-    measurements = unwrapLegacyMeasurements(measurements || ReactDefaultPerf._allMeasurements);
-    console.table(ReactDefaultPerf.getWasted(measurements));
-    console.log(
-      'Total time:',
-      ReactDefaultPerfAnalysis.getTotalTime(measurements).toFixed(2) + ' ms'
-    );
-  },
-
-  printDOM: function(measurements) {
-    warning(
-      warnedAboutPrintDOM,
-      '`ReactPerf.printDOM(...)` is deprecated. Use ' +
-      '`ReactPerf.printOperations(...)` instead.'
-    );
-    warnedAboutPrintDOM = true;
-    return ReactDefaultPerf.printOperations(measurements);
-  },
-
-  printOperations: function(measurements) {
-    measurements = unwrapLegacyMeasurements(measurements || ReactDefaultPerf._allMeasurements);
-    var summary = ReactDefaultPerfAnalysis.getDOMSummary(measurements);
-    console.table(summary.map(function(item) {
-      var result = {};
-      result[DOMProperty.ID_ATTRIBUTE_NAME] = item.id;
-      result.type = item.type;
-      result.args = JSON.stringify(item.args, stripComplexValues);
-      return result;
-    }));
-    console.log(
-      'Total time:',
-      ReactDefaultPerfAnalysis.getTotalTime(measurements).toFixed(2) + ' ms'
-    );
-  },
-
-  _recordWrite: function(id, fnName, totalTime, args) {
-    // TODO: totalTime isn't that useful since it doesn't count paints/reflows
-    var entry =
-      ReactDefaultPerf
-        ._allMeasurements[ReactDefaultPerf._allMeasurements.length - 1];
-    var writes = entry.writes;
-    writes[id] = writes[id] || [];
-    writes[id].push({
-      type: fnName,
-      time: totalTime,
-      args: args,
-    });
-  },
-
-  measure: function(moduleName, fnName, func) {
-    return function(...args) {
-      var totalTime;
-      var rv;
-      var start;
-
-      var entry = ReactDefaultPerf._allMeasurements[
-        ReactDefaultPerf._allMeasurements.length - 1
-      ];
-
-      if (fnName === '_renderNewRootComponent' ||
-          fnName === 'flushBatchedUpdates') {
-        // A "measurement" is a set of metrics recorded for each flush. We want
-        // to group the metrics for a given flush together so we can look at the
-        // components that rendered and the DOM operations that actually
-        // happened to determine the amount of "wasted work" performed.
-        ReactDefaultPerf._allMeasurements.push(entry = {
-          exclusive: {},
-          inclusive: {},
-          render: {},
-          counts: {},
-          writes: {},
-          displayNames: {},
-          hierarchy: {},
-          totalTime: 0,
-          created: {},
-        });
-        start = performanceNow();
-        rv = func.apply(this, args);
-        entry.totalTime = performanceNow() - start;
-        return rv;
-      } else if (fnName === '_mountImageIntoNode' ||
-          moduleName === 'ReactDOMIDOperations' ||
-          moduleName === 'CSSPropertyOperations' ||
-          moduleName === 'DOMChildrenOperations' ||
-          moduleName === 'DOMPropertyOperations' ||
-          moduleName === 'ReactComponentBrowserEnvironment') {
-        start = performanceNow();
-        rv = func.apply(this, args);
-        totalTime = performanceNow() - start;
-
-        if (fnName === '_mountImageIntoNode') {
-          ReactDefaultPerf._recordWrite('', fnName, totalTime, args[0]);
-        } else if (fnName === 'dangerouslyProcessChildrenUpdates') {
-          // special format
-          args[1].forEach(function(update) {
-            var writeArgs = {};
-            if (update.fromIndex !== null) {
-              writeArgs.fromIndex = update.fromIndex;
-            }
-            if (update.toIndex !== null) {
-              writeArgs.toIndex = update.toIndex;
-            }
-            if (update.content !== null) {
-              writeArgs.content = update.content;
-            }
-            ReactDefaultPerf._recordWrite(
-              args[0]._rootNodeID,
-              update.type,
-              totalTime,
-              writeArgs
-            );
-          });
-        } else {
-          // basic format
-          var id = args[0];
-          if (moduleName === 'EventPluginHub') {
-            id = id._rootNodeID;
-          } else if (fnName === 'replaceNodeWithMarkup') {
-            // Old node is already unmounted; can't get its instance
-            id = ReactDOMComponentTree.getInstanceFromNode(args[1].node)._rootNodeID;
-          } else if (fnName === 'replaceDelimitedText') {
-            id = getID(ReactDOMComponentTree.getInstanceFromNode(args[0]));
-          } else if (typeof id === 'object') {
-            id = getID(ReactDOMComponentTree.getInstanceFromNode(args[0]));
-          }
-          ReactDefaultPerf._recordWrite(
-            id,
-            fnName,
-            totalTime,
-            Array.prototype.slice.call(args, 1)
-          );
-        }
-        return rv;
-      } else if (moduleName === 'ReactCompositeComponent' && (
-        fnName === 'mountComponent' ||
-        fnName === 'updateComponent' || // TODO: receiveComponent()?
-        fnName === '_renderValidatedComponent')) {
-
-        if (this._currentElement.type === ReactMount.TopLevelWrapper) {
-          return func.apply(this, args);
-        }
-
-        var rootNodeID = getIDOfComposite(this);
-        var isRender = fnName === '_renderValidatedComponent';
-        var isMount = fnName === 'mountComponent';
-
-        var mountStack = ReactDefaultPerf._mountStack;
-
-        if (isRender) {
-          addValue(entry.counts, rootNodeID, 1);
-        } else if (isMount) {
-          entry.created[rootNodeID] = true;
-          mountStack.push(0);
-        }
-
-        ReactDefaultPerf._compositeStack.push(rootNodeID);
-
-        start = performanceNow();
-        rv = func.apply(this, args);
-        totalTime = performanceNow() - start;
-
-        ReactDefaultPerf._compositeStack.pop();
-
-        if (isRender) {
-          addValue(entry.render, rootNodeID, totalTime);
-        } else if (isMount) {
-          var subMountTime = mountStack.pop();
-          mountStack[mountStack.length - 1] += totalTime;
-          addValue(entry.exclusive, rootNodeID, totalTime - subMountTime);
-          addValue(entry.inclusive, rootNodeID, totalTime);
-        } else {
-          addValue(entry.inclusive, rootNodeID, totalTime);
-        }
-
-        entry.displayNames[rootNodeID] = {
-          current: this.getName(),
-          owner: this._currentElement._owner ?
-            this._currentElement._owner.getName() :
-            '<root>',
-        };
-
-        return rv;
-      } else if (
-        (moduleName === 'ReactDOMComponent' ||
-         moduleName === 'ReactDOMTextComponent') &&
-        (fnName === 'mountComponent' ||
-         fnName === 'receiveComponent')) {
-
-        rv = func.apply(this, args);
-        entry.hierarchy[getID(this)] =
-          ReactDefaultPerf._compositeStack.slice();
-        return rv;
-      } else {
-        return func.apply(this, args);
-      }
-    };
-  },
-};
-
-module.exports = ReactDefaultPerf;
diff --git a/src/test/ReactDefaultPerfAnalysis.js b/src/test/ReactDefaultPerfAnalysis.js
deleted file mode 100644
index bb5a35e2d0..0000000000
--- a/src/test/ReactDefaultPerfAnalysis.js
+++ /dev/null
@@ -1,214 +0,0 @@
-/**
- * Copyright 2013-present, Facebook, Inc.
- * All rights reserved.
- *
- * This source code is licensed under the BSD-style license found in the
- * LICENSE file in the root directory of this source tree. An additional grant
- * of patent rights can be found in the PATENTS file in the same directory.
- *
- * @providesModule ReactDefaultPerfAnalysis
- */
-
-'use strict';
-
-
-// Don't try to save users less than 1.2ms (a number I made up)
-var DONT_CARE_THRESHOLD = 1.2;
-var DOM_OPERATION_TYPES = {
-  '_mountImageIntoNode': 'set innerHTML',
-  INSERT_MARKUP: 'set innerHTML',
-  MOVE_EXISTING: 'move',
-  REMOVE_NODE: 'remove',
-  SET_MARKUP: 'set innerHTML',
-  TEXT_CONTENT: 'set textContent',
-  'setValueForProperty': 'update attribute',
-  'setValueForAttribute': 'update attribute',
-  'deleteValueForProperty': 'remove attribute',
-  'setValueForStyles': 'update styles',
-  'replaceNodeWithMarkup': 'replace',
-  'replaceDelimitedText': 'replace',
-};
-
-function getTotalTime(measurements) {
-  // TODO: return number of DOM ops? could be misleading.
-  // TODO: measure dropped frames after reconcile?
-  // TODO: log total time of each reconcile and the top-level component
-  // class that triggered it.
-  var totalTime = 0;
-  for (var i = 0; i < measurements.length; i++) {
-    var measurement = measurements[i];
-    totalTime += measurement.totalTime;
-  }
-  return totalTime;
-}
-
-function getDOMSummary(measurements) {
-  var items = [];
-  measurements.forEach(function(measurement) {
-    Object.keys(measurement.writes).forEach(function(id) {
-      measurement.writes[id].forEach(function(write) {
-        items.push({
-          id: id,
-          type: DOM_OPERATION_TYPES[write.type] || write.type,
-          args: write.args,
-        });
-      });
-    });
-  });
-  return items;
-}
-
-function getExclusiveSummary(measurements) {
-  var candidates = {};
-  var displayName;
-
-  for (var i = 0; i < measurements.length; i++) {
-    var measurement = measurements[i];
-    var allIDs = Object.assign(
-      {},
-      measurement.exclusive,
-      measurement.inclusive
-    );
-
-    for (var id in allIDs) {
-      displayName = measurement.displayNames[id].current;
-
-      candidates[displayName] = candidates[displayName] || {
-        componentName: displayName,
-        inclusive: 0,
-        exclusive: 0,
-        render: 0,
-        count: 0,
-      };
-      if (measurement.render[id]) {
-        candidates[displayName].render += measurement.render[id];
-      }
-      if (measurement.exclusive[id]) {
-        candidates[displayName].exclusive += measurement.exclusive[id];
-      }
-      if (measurement.inclusive[id]) {
-        candidates[displayName].inclusive += measurement.inclusive[id];
-      }
-      if (measurement.counts[id]) {
-        candidates[displayName].count += measurement.counts[id];
-      }
-    }
-  }
-
-  // Now make a sorted array with the results.
-  var arr = [];
-  for (displayName in candidates) {
-    if (candidates[displayName].exclusive >= DONT_CARE_THRESHOLD) {
-      arr.push(candidates[displayName]);
-    }
-  }
-
-  arr.sort(function(a, b) {
-    return b.exclusive - a.exclusive;
-  });
-
-  return arr;
-}
-
-function getInclusiveSummary(measurements, onlyClean) {
-  var candidates = {};
-  var inclusiveKey;
-
-  for (var i = 0; i < measurements.length; i++) {
-    var measurement = measurements[i];
-    var allIDs = Object.assign(
-      {},
-      measurement.exclusive,
-      measurement.inclusive
-    );
-    var cleanComponents;
-
-    if (onlyClean) {
-      cleanComponents = getUnchangedComponents(measurement);
-    }
-
-    for (var id in allIDs) {
-      if (onlyClean && !cleanComponents[id]) {
-        continue;
-      }
-
-      var displayName = measurement.displayNames[id];
-
-      // Inclusive time is not useful for many components without knowing where
-      // they are instantiated. So we aggregate inclusive time with both the
-      // owner and current displayName as the key.
-      inclusiveKey = displayName.owner + ' > ' + displayName.current;
-
-      candidates[inclusiveKey] = candidates[inclusiveKey] || {
-        componentName: inclusiveKey,
-        time: 0,
-        count: 0,
-      };
-
-      if (measurement.inclusive[id]) {
-        candidates[inclusiveKey].time += measurement.inclusive[id];
-      }
-      if (measurement.counts[id]) {
-        candidates[inclusiveKey].count += measurement.counts[id];
-      }
-    }
-  }
-
-  // Now make a sorted array with the results.
-  var arr = [];
-  for (inclusiveKey in candidates) {
-    if (candidates[inclusiveKey].time >= DONT_CARE_THRESHOLD) {
-      arr.push(candidates[inclusiveKey]);
-    }
-  }
-
-  arr.sort(function(a, b) {
-    return b.time - a.time;
-  });
-
-  return arr;
-}
-
-function getUnchangedComponents(measurement) {
-  // For a given reconcile, look at which components did not actually
-  // render anything to the DOM and return a mapping of their ID to
-  // the amount of time it took to render the entire subtree.
-  var cleanComponents = {};
-  var writes = measurement.writes;
-  var hierarchy = measurement.hierarchy;
-  var dirtyComposites = {};
-  Object.keys(writes).forEach(function(id) {
-    writes[id].forEach(function(write) {
-      // Root mounting (innerHTML set) is recorded with an ID of ''
-      if (id !== '' && hierarchy.hasOwnProperty(id)) {
-        hierarchy[id].forEach((c) => dirtyComposites[c] = true);
-      }
-    });
-  });
-  var allIDs = Object.assign({}, measurement.exclusive, measurement.inclusive);
-
-  for (var id in allIDs) {
-    var isDirty = false;
-    // See if any of the DOM operations applied to this component's subtree.
-    if (dirtyComposites[id]) {
-      isDirty = true;
-    }
-    // check if component newly created
-    if (measurement.created[id]) {
-      isDirty = true;
-    }
-    if (!isDirty && measurement.counts[id] > 0) {
-      cleanComponents[id] = true;
-    }
-  }
-  return cleanComponents;
-}
-
-var ReactDefaultPerfAnalysis = {
-  getExclusiveSummary: getExclusiveSummary,
-  getInclusiveSummary: getInclusiveSummary,
-  getDOMSummary: getDOMSummary,
-  getTotalTime: getTotalTime,
-};
-
-module.exports = ReactDefaultPerfAnalysis;
diff --git a/src/test/ReactPerf.js b/src/test/ReactPerf.js
deleted file mode 100644
index 1eb803a4e8..0000000000
--- a/src/test/ReactPerf.js
+++ /dev/null
@@ -1,99 +0,0 @@
-/**
- * Copyright 2013-present, Facebook, Inc.
- * All rights reserved.
- *
- * This source code is licensed under the BSD-style license found in the
- * LICENSE file in the root directory of this source tree. An additional grant
- * of patent rights can be found in the PATENTS file in the same directory.
- *
- * @providesModule ReactPerf
- */
-
-'use strict';
-
-/**
- * ReactPerf is a general AOP system designed to measure performance. This
- * module only has the hooks: see ReactDefaultPerf for the analysis tool.
- */
-var ReactPerf = {
-  /**
-   * Boolean to enable/disable measurement. Set to false by default to prevent
-   * accidental logging and perf loss.
-   */
-  enableMeasure: false,
-
-  /**
-   * Holds onto the measure function in use. By default, don't measure
-   * anything, but we'll override this if we inject a measure function.
-   */
-  storedMeasure: _noMeasure,
-
-  /**
-   * @param {object} object
-   * @param {string} objectName
-   * @param {object<string>} methodNames
-   */
-  measureMethods: function(object, objectName, methodNames) {
-    if (__DEV__) {
-      for (var key in methodNames) {
-        if (!methodNames.hasOwnProperty(key)) {
-          continue;
-        }
-        object[key] = ReactPerf.measure(
-          objectName,
-          methodNames[key],
-          object[key]
-        );
-      }
-    }
-  },
-
-  /**
-   * Use this to wrap methods you want to measure. Zero overhead in production.
-   *
-   * @param {string} objName
-   * @param {string} fnName
-   * @param {function} func
-   * @return {function}
-   */
-  measure: function(objName, fnName, func) {
-    if (__DEV__) {
-      var measuredFunc = null;
-      var wrapper = function() {
-        if (ReactPerf.enableMeasure) {
-          if (!measuredFunc) {
-            measuredFunc = ReactPerf.storedMeasure(objName, fnName, func);
-          }
-          return measuredFunc.apply(this, arguments);
-        }
-        return func.apply(this, arguments);
-      };
-      wrapper.displayName = objName + '_' + fnName;
-      return wrapper;
-    }
-    return func;
-  },
-
-  injection: {
-    /**
-     * @param {function} measure
-     */
-    injectMeasure: function(measure) {
-      ReactPerf.storedMeasure = measure;
-    },
-  },
-};
-
-/**
- * Simply passes through the measured function, without measuring it.
- *
- * @param {string} objName
- * @param {string} fnName
- * @param {function} func
- * @return {function}
- */
-function _noMeasure(objName, fnName, func) {
-  return func;
-}
-
-module.exports = ReactPerf;
diff --git a/src/test/ReactTestUtils.js b/src/test/ReactTestUtils.js
index 0e6b19150f..af5b860f85 100644
--- a/src/test/ReactTestUtils.js
+++ b/src/test/ReactTestUtils.js
@@ -71,6 +71,10 @@ function findAllInRenderedTreeInternal(inst, test) {
 }
 
 /**
+ * Utilities for making it easy to test React components.
+ *
+ * See https://facebook.github.io/react/docs/test-utils.html
+ *
  * Todo: Support the entire DOM.scry query syntax. For now, these simple
  * utilities will suffice for testing purposes.
  * @lends ReactTestUtils
@@ -372,9 +376,12 @@ ReactShallowRenderer.prototype.getMountedInstance = function() {
   return this._instance ? this._instance._instance : null;
 };
 
+var nextDebugID = 1;
+
 var NoopInternalComponent = function(element) {
   this._renderedOutput = element;
   this._currentElement = element;
+  this._debugID = nextDebugID++;
 };
 
 NoopInternalComponent.prototype = {
@@ -400,6 +407,7 @@ NoopInternalComponent.prototype = {
 };
 
 var ShallowComponentWrapper = function(element) {
+  this._debugID = nextDebugID++;
   this.construct(element);
 };
 Object.assign(
diff --git a/src/test/__tests__/ReactTestUtils-test.js b/src/test/__tests__/ReactTestUtils-test.js
index 9423381ca4..493e88e4bd 100644
--- a/src/test/__tests__/ReactTestUtils-test.js
+++ b/src/test/__tests__/ReactTestUtils-test.js
@@ -89,7 +89,7 @@ describe('ReactTestUtils', function() {
   });
 
   it('should have shallow unmounting', function() {
-    var componentWillUnmount = jest.genMockFn();
+    var componentWillUnmount = jest.fn();
 
     var SomeComponent = React.createClass({
       render: function() {