Make classes and structures in core/dom fast-allocated.

Source/core/dom/ElementDataCache.h

 /*
  * Copyright (C) 2012, 2013 Apple 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:
  * 1. Redistributions of source code must retain the above copyright
  *    notice, this list of conditions and the following disclaimer.
  * 2. Redistributions in binary form must reproduce the above copyright
  *    notice, this list of conditions and the following disclaimer in the
@@ skipping 23 matching lines @@
 #include "wtf/RefPtr.h"
 #include "wtf/Vector.h"
 #include "wtf/text/StringHash.h"
 
 namespace blink {
 
 class Attribute;
 class ShareableElementData;
 
 class ElementDataCache final : public NoBaseWillBeGarbageCollected<ElementDataCache>  {
+    WTF_MAKE_FAST_ALLOCATED_WILL_BE_REMOVED(ElementDataCache);
     DECLARE_EMPTY_DESTRUCTOR_WILL_BE_REMOVED(ElementDataCache)
 public:
     static PassOwnPtrWillBeRawPtr<ElementDataCache> create() { return adoptPtrWillBeNoop(new ElementDataCache); }
 
     PassRefPtrWillBeRawPtr<ShareableElementData> cachedShareableElementDataWithAttributes(const Vector<Attribute>&);
 
     DECLARE_TRACE();
 
 private:
     ElementDataCache();
 
     typedef WillBeHeapHashMap<unsigned, RefPtrWillBeMember<ShareableElementData>, AlreadyHashed> ShareableElementDataCache;
     ShareableElementDataCache m_shareableElementDataCache;
 };
 
 }
 
 #endif