Bring in Facebook's requestAnimationFrame module

src/vendor/core/requestAnimationFrame.js

@@ -0,0 +1,37 @@
+/**
+ * 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 requestAnimationFrame
+ */
+
+var emptyFunction = require('emptyFunction');
+
+var requestAnimationFrame =
+  window.requestAnimationFrame       ||
+  window.webkitRequestAnimationFrame ||
+  window.mozRequestAnimationFrame    ||
+  window.oRequestAnimationFrame      ||
+  window.msRequestAnimationFrame     ||
+  function(callback) {
+    // Browsers which don't support requestAnimationFrame are likely running on
+    // older hardware, so it's not reasonable to expect 60FPS animations out of
+    // them. 30FPS (33.3ms per frame) is more reasonable.
+    return window.setTimeout(callback, 33);
+  };
+
+// Works around a rare bug in Safari 6 where the first request is never invoked.
+requestAnimationFrame(emptyFunction);
+
+module.exports = requestAnimationFrame;