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

Source/core/dom/ElementRareData.cpp

 /*
  * Copyright (C) 2012 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 22 matching lines @@
 
 #include "core/style/ComputedStyle.h"
 
 namespace blink {
 
 struct SameSizeAsElementRareData : NodeRareData {
     short indices[2];
     LayoutSize sizeForResizing;
     IntSize scrollOffset;
     void* pointers[14];
+#if !ENABLE(OILPAN)
+    // TODO: Decide to add following element to check persistent.
+    void* persistents[1][5];
+#endif

[peria, 2015/05/01 07:50:28]

NOTE:
With this change, the size of ElementRareData class becomes 200 Bytes from 160
Bytes, on non-Oilpan build.
It will be back to 160 Bytes if ElementRareData moves to Oilpan heap.

[haraken, 2015/05/01 09:04:07]

This is because sizeof(Persistent) is too large. I'm trying to reduce the size.

 };
 
 CSSStyleDeclaration& ElementRareData::ensureInlineCSSStyleDeclaration(Element* ownerElement)
 {
     if (!m_cssomWrapper)
         m_cssomWrapper = adoptPtrWillBeNoop(new InlineCSSStyleDeclaration(ownerElement));
     return *m_cssomWrapper;
 }
 
 WillBeHeapVector<RefPtrWillBeMember<Attr>>& ElementRareData::ensureAttrNodeList()
@@ skipping 19 matching lines @@
     visitor->trace(m_generatedBefore);
     visitor->trace(m_generatedAfter);
     visitor->trace(m_generatedFirstLetter);
     visitor->trace(m_backdrop);
     NodeRareData::traceAfterDispatch(visitor);
 }
 
 static_assert(sizeof(ElementRareData) == sizeof(SameSizeAsElementRareData), "ElementRareData should stay small");
 
 } // namespace blink