[Oilpan] Migrate most classes under core/animations to Oilpan heap.

Source/core/animation/AnimationNode.idl

 /*
  * Copyright (C) 2013 Google Inc. All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions are
  * met:
  *
  *     * Redistributions of source code must retain the above copyright
  * notice, this list of conditions and the following disclaimer.
  *     * Redistributions in binary form must reproduce the above
@@ skipping 18 matching lines @@
  */
 
 // http://www.w3.org/TR/web-animations/#the-animationnode-interface
 
 // TODO(dstockwell): This interface has been renamed to AnimationEffectReadonly
 // in the latest spec:
 // https://w3c.github.io/web-animations/#the-animationeffectreadonly-interface
 
 [
     RuntimeEnabled=WebAnimationsAPI,
-    WillBeGarbageCollected,
+    GarbageCollected,
 ] interface AnimationNode {
     readonly attribute Timing timing;
     readonly attribute ComputedTimingProperties computedTiming;
 };