Fixing Window.animationFrame timing issue

sdk/lib/html/dartium/html_dartium.dart

Index: sdk/lib/html/dartium/html_dartium.dart
diff --git a/sdk/lib/html/dartium/html_dartium.dart b/sdk/lib/html/dartium/html_dartium.dart
index be4fb4fc59932c2cff8b16e1189b08a22b52ccba..59a84f6a0510f72788418b7eb4e46fecd9756e8c 100644
--- a/sdk/lib/html/dartium/html_dartium.dart
+++ b/sdk/lib/html/dartium/html_dartium.dart
@@ -27952,13 +27952,13 @@ class Url extends NativeFieldWrapperClass2 {
     if ((blob_OR_source_OR_stream is Blob || blob_OR_source_OR_stream == null)) {
       return _createObjectURL_1(blob_OR_source_OR_stream);
     }
-    if ((blob_OR_source_OR_stream is MediaSource || blob_OR_source_OR_stream == null)) {
+    if ((blob_OR_source_OR_stream is MediaStream || blob_OR_source_OR_stream == null)) {
       return _createObjectURL_2(blob_OR_source_OR_stream);
     }
-    if ((blob_OR_source_OR_stream is _WebKitMediaSource || blob_OR_source_OR_stream == null)) {
+    if ((blob_OR_source_OR_stream is MediaSource || blob_OR_source_OR_stream == null)) {
       return _createObjectURL_3(blob_OR_source_OR_stream);
     }
-    if ((blob_OR_source_OR_stream is MediaStream || blob_OR_source_OR_stream == null)) {
+    if ((blob_OR_source_OR_stream is _WebKitMediaSource || blob_OR_source_OR_stream == null)) {
       return _createObjectURL_4(blob_OR_source_OR_stream);
     }
     throw new ArgumentError("Incorrect number or type of arguments");
@@ -28555,7 +28555,7 @@ class Window extends EventTarget implements WindowBase, _WindowTimers, WindowBas
    * [animationFrame] again for the animation to continue.
    */
   Future<num> get animationFrame {
-    var completer = new Completer<num>();
+    var completer = new Completer<num>.sync();
     requestAnimationFrame((time) {
       completer.complete(time);
     });
@@ -37055,26 +37055,26 @@ final _pureIsolateUriBaseClosure = () {
 };
 
 class _Timer implements Timer {
-  const int _STATE_TIMEOUT = 0;
-  const int _STATE_INTERVAL = 1;
-  var _state;
+  static const int _STATE_TIMEOUT = 0;
+  static const int _STATE_INTERVAL = 1;
+  int _state;
 
   _Timer(int milliSeconds, void callback(Timer timer), bool repeating) {
     if (repeating) {
-      _state = window._setInterval(() {
+      _state = (window._setInterval(() {
         callback(this);
-      }, milliSeconds) * 2 + _STATE_INTERVAL;
+      }, milliSeconds) << 1) | _STATE_INTERVAL;
     } else {
-      _state = window._setTimeout(() {
+      _state = (window._setTimeout(() {
         _state = null;
         callback(this);
-      }, milliSeconds) * 2 + _STATE_TIMEOUT;
+      }, milliSeconds) << 1) | _STATE_TIMEOUT;
     }
   }
 
   void cancel() {
     if (_state == null) return;
-    int id = _state ~/ 2;
+    int id = _state >> 1;
     if ((_state & 1) == _STATE_TIMEOUT) {
       window._clearTimeout(id);
     } else {