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

Source/core/dom/ElementRareData.h

Index: Source/core/dom/ElementRareData.h
diff --git a/Source/core/dom/ElementRareData.h b/Source/core/dom/ElementRareData.h
index 602417d203c834b3f45fcf26f205b82722bb3e56..a762b8863ef4a3f40a15860e6556317154a6ba05 100644
--- a/Source/core/dom/ElementRareData.h
+++ b/Source/core/dom/ElementRareData.h
@@ -107,7 +107,7 @@ public:
     void setSavedLayerScrollOffset(IntSize size) { m_savedLayerScrollOffset = size; }
 
     ElementAnimations* elementAnimations() { return m_elementAnimations.get(); }
-    void setElementAnimations(PassOwnPtrWillBeRawPtr<ElementAnimations> elementAnimations)
+    void setElementAnimations(ElementAnimations* elementAnimations)
     {
         m_elementAnimations = elementAnimations;
     }
@@ -154,7 +154,7 @@ private:
     OwnPtrWillBeMember<NamedNodeMap> m_attributeMap;
     OwnPtrWillBeMember<AttrNodeList> m_attrNodeList;
     OwnPtrWillBeMember<InputMethodContext> m_inputMethodContext;
-    OwnPtrWillBeMember<ElementAnimations> m_elementAnimations;
+    PersistentWillBeMember<ElementAnimations> m_elementAnimations;
     OwnPtrWillBeMember<InlineCSSStyleDeclaration> m_cssomWrapper;
 
     RefPtr<ComputedStyle> m_computedStyle;