Add pre finalizer to Animation to ensure compositor handles get cleaned up

third_party/WebKit/Source/core/animation/Animation.cpp

 /*
  * 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 885 matching lines @@
 
 void Animation::endUpdatingState()
 {
     ASSERT(m_stateIsBeingUpdated);
     m_stateIsBeingUpdated = false;
 }
 
 void Animation::createCompositorPlayer()
 {
     if (Platform::current()->isThreadedAnimationEnabled() && !m_compositorPlayer) {
+        // We only need to pre-finalize if we are running animations on the compositor.
+        ThreadState::current()->registerPreFinalizer(this);
+
         ASSERT(Platform::current()->compositorSupport());
         m_compositorPlayer = CompositorAnimationPlayer::create();
         ASSERT(m_compositorPlayer);
         m_compositorPlayer->setAnimationDelegate(this);
         attachCompositorTimeline();
     }
 
     attachCompositedLayers();
 }
 
@@ skipping 177 matching lines @@
     visitor->trace(m_timeline);
     visitor->trace(m_pendingFinishedEvent);
     visitor->trace(m_pendingCancelledEvent);
     visitor->trace(m_finishedPromise);
     visitor->trace(m_readyPromise);
     EventTargetWithInlineData::trace(visitor);
     ActiveDOMObject::trace(visitor);
 }
 
 } // namespace blink