Make ReactDefaultPerf work server-side

We were reading from window which was throwing when ReactDefaultPerf was injected.

src/test/ReactDefaultPerf.js

@@ -19,6 +19,8 @@
 
 "use strict";
 
+var performanceNow = require('performanceNow');
+
 var ReactDefaultPerf = {};
 
 if (__DEV__) {
@@ -186,9 +188,9 @@ if (__DEV__) {
       var fnArgs = _getFnArguments(func);
 
       return function() {
-        var timeBeforeFn = now();
+        var timeBeforeFn = performanceNow();
         var fnReturn = func.apply(this, arguments);
-        var timeAfterFn = now();
+        var timeAfterFn = performanceNow();
 
         /**
          * Hold onto arguments in a readable way: args[1] -> args.component.
@@ -224,7 +226,7 @@ if (__DEV__) {
         var callback = _getCallback(objName, fnName);
         callback && callback(this, args, fnReturn, log, info);
 
-        log.timing.timeToLog = now() - timeAfterFn;
+        log.timing.timeToLog = performanceNow() - timeAfterFn;
 
         return fnReturn;
       };
@@ -400,17 +402,6 @@ if (__DEV__) {
   var _microTime = function(time) {
     return Math.round(time * 1000) / 1000;
   };
-
-  /**
-   * Shim window.performance.now
-   * We can't assign window.performance.now and then call it, so need to bind.
-   * TODO: Support Firefox < 15 for now
-   */
-  var performance = window && (window.performance || window.webkitPeformance);
-  if (!performance || !performance.now) {
-    performance = Date;
-  }
-  var now = performance.now.bind(performance);
 }
 
 module.exports = ReactDefaultPerf;

src/test/performanceNow.js

@@ -0,0 +1,42 @@
+/**
+ * Copyright 2013 Facebook, Inc.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ *
+ * @providesModule performanceNow
+ * @typechecks static-only
+ */
+
+"use strict";
+
+var ExecutionEnvironment = require('ExecutionEnvironment');
+
+/**
+ * Detect if we can use window.performance.now() and gracefully
+ * fallback to Date.now() if it doesn't exist.
+ * We need to support Firefox < 15 for now due to Facebook's webdriver
+ * infrastructure.
+ */
+var performance = null;
+
+if (ExecutionEnvironment.canUseDOM) {
+  performance = window.performance || window.webkitPerformance;
+}
+
+if (!performance || !performance.now) {
+  performance = Date;
+}
+
+var performanceNow = performance.now.bind(performance);
+
+module.exports = performanceNow;