Separate performanceNow into own project

src/vendor/performance/performance.js

@@ -0,0 +1,33 @@
+/**
+ * Copyright 2013-2014 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 performance
+ * @typechecks
+ */
+
+"use strict";
+
+var ExecutionEnvironment = require('ExecutionEnvironment');
+
+var performance;
+
+if (ExecutionEnvironment.canUseDOM) {
+  performance =
+    window.performance ||
+    window.msPerformance ||
+    window.webkitPerformance;
+}
+
+module.exports = performance || {};

src/vendor/performance/performanceNow.js

@@ -14,25 +14,16 @@
  * limitations under the License.
  *
  * @providesModule performanceNow
- * @typechecks static-only
+ * @typechecks
  */
 
-"use strict";
-
-var ExecutionEnvironment = require('ExecutionEnvironment');
+var performance = require('performance');
 
 /**
- * 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.
+ * 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
+ * because of Facebook's testing infrastructure.
  */
-var performance = null;
-
-if (ExecutionEnvironment.canUseDOM) {
-  performance = window.performance || window.webkitPerformance;
-}
-
 if (!performance || !performance.now) {
   performance = Date;
 }