[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 bcd739cf05d7d796782502e1998914bdb2390157..bcf990dca893a9073661d717c89a46de8f822089 100644
--- a/Source/core/dom/ElementRareData.h
+++ b/Source/core/dom/ElementRareData.h
@@ -102,7 +102,7 @@ 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;
     }
@@ -141,7 +141,7 @@ private:
     OwnPtrWillBeMember<ElementShadow> m_shadow;
     OwnPtrWillBeMember<NamedNodeMap> m_attributeMap;
     OwnPtrWillBeMember<AttrNodeList> m_attrNodeList;
-    OwnPtrWillBeMember<ElementAnimations> m_elementAnimations;
+    PersistentWillBeMember<ElementAnimations> m_elementAnimations;
     OwnPtrWillBeMember<InlineCSSStyleDeclaration> m_cssomWrapper;
 
     RefPtr<ComputedStyle> m_computedStyle;