[oilpan]: Move ElementDataCache to the oilpan heap using transition types.

Source/core/dom/ElementDataCache.cpp

 /*
  * 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 13 matching lines @@
  *
  */
 
 #include "config.h"
 #include "core/dom/ElementDataCache.h"
 
 #include "core/dom/ElementData.h"
 
 namespace WebCore {
 
+DEFINE_EMPTY_DESTRUCTOR_WILL_BE_REMOVED(ElementDataCache)
+
 inline unsigned attributeHash(const Vector<Attribute>& attributes)
 {
     return StringHasher::hashMemory(attributes.data(), attributes.size() * sizeof(Attribute));
 }
 
 inline bool hasSameAttributes(const Vector<Attribute>& attributes, ShareableElementData& elementData)
 {
     if (attributes.size() != elementData.attributes().size())
         return false;
     return !memcmp(attributes.data(), elementData.m_attributeArray, attributes.size() * sizeof(Attribute));
@@ skipping 12 matching lines @@
     if (!it->value)
         it->value = ShareableElementData::createWithAttributes(attributes);
 
     return it->value.get();
 }
 
 ElementDataCache::ElementDataCache()
 {
 }
 
-ElementDataCache::~ElementDataCache()
+void ElementDataCache::trace(Visitor* visitor)
 {
+    visitor->trace(m_shareableElementDataCache);
 }
 
 }