Revert "Browser compat for window.requestAnimationFrame"

lib/html/dartium/html_dartium.dart

Index: lib/html/dartium/html_dartium.dart
diff --git a/lib/html/dartium/html_dartium.dart b/lib/html/dartium/html_dartium.dart
index 544f3b0bbfd2100e43759ee0e2b6b77fa33a7a2a..2db035463ca0fd2b9f3c6cb2d9271509b0cc1534 100644
--- a/lib/html/dartium/html_dartium.dart
+++ b/lib/html/dartium/html_dartium.dart
@@ -21314,9 +21314,6 @@ class _WindowImpl extends _EventTargetImpl implements Window {
     _addMeasurementFrameCallback(callback);
   }
 
-  int requestAnimationFrame(RequestAnimationFrameCallback callback) =>
-      webkitRequestAnimationFrame(callback);
-
   _WindowImpl._wrap(ptr) : super._wrap(ptr);
 
   _WindowEventsImpl get on() {
@@ -39785,10 +39782,6 @@ interface Window extends EventTarget {
   void requestLayoutFrame(TimeoutHandler callback);
 
 
-  /** @domName DOMWindow.webkitRequestAnimationFrame */
-  int requestAnimationFrame(RequestAnimationFrameCallback callback);
-
-
   /**
    * @domName EventTarget.addEventListener, EventTarget.removeEventListener, EventTarget.dispatchEvent
    */