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

Source/core/animation/CompositorPendingAnimations.h

Index: Source/core/animation/CompositorPendingAnimations.h
diff --git a/Source/core/animation/CompositorPendingAnimations.h b/Source/core/animation/CompositorPendingAnimations.h
index 03e81c3cd0c8d8e99b4381fd5b846cc329412d80..ffa024224e0f0af301261f4508e615a23fc88929 100644
--- a/Source/core/animation/CompositorPendingAnimations.h
+++ b/Source/core/animation/CompositorPendingAnimations.h
@@ -64,8 +64,8 @@ public:
 private:
     void timerFired(Timer<CompositorPendingAnimations>*) { update(false); }
 
-    WillBeHeapVector<RefPtrWillBeMember<Animation>> m_pending;
-    WillBeHeapVector<RefPtrWillBeMember<Animation>> m_waitingForCompositorAnimationStart;
+    PersistentHeapVectorWillBeHeapVector<Member<Animation>> m_pending;
+    PersistentHeapVectorWillBeHeapVector<Member<Animation>> m_waitingForCompositorAnimationStart;
     Timer<CompositorPendingAnimations> m_timer;
     int m_compositorGroup;
 };