Oilpan: move node/element rare data objects to the heap.

Source/core/dom/Document.cpp

 /*
  * Copyright (C) 1999 Lars Knoll (knoll@kde.org)
  *           (C) 1999 Antti Koivisto (koivisto@kde.org)
  *           (C) 2001 Dirk Mueller (mueller@kde.org)
  *           (C) 2006 Alexey Proskuryakov (ap@webkit.org)
  * Copyright (C) 2004, 2005, 2006, 2007, 2008, 2009, 2011, 2012 Apple Inc. All rights reserved.
  * Copyright (C) 2008, 2009 Torch Mobile Inc. All rights reserved. (http://www.torchmobile.com/)
  * Copyright (C) 2008, 2009, 2011, 2012 Google Inc. All rights reserved.
  * Copyright (C) 2010 Nokia Corporation and/or its subsidiary(-ies)
  * Copyright (C) Research In Motion Limited 2010-2011. All rights reserved.
@@ skipping 573 matching lines @@
 
     // It's possible for multiple Documents to end up referencing the same ResourceFetcher (e.g., SVGImages
     // load the initial empty document and the SVGDocument with the same DocumentLoader).
     if (m_fetcher->document() == this)
         m_fetcher->setDocument(nullptr);
     m_fetcher.clear();
 #endif
 
     // We must call clearRareData() here since a Document class inherits TreeScope
     // as well as Node. See a comment on TreeScope.h for the reason.
+#if !ENABLE(OILPAN)
     if (hasRareData())
         clearRareData();
+#endif
 
     ASSERT(!m_listsInvalidatedAtDocument.size());
 
     for (unsigned i = 0; i < WTF_ARRAY_LENGTH(m_nodeListCounts); i++)
         ASSERT(!m_nodeListCounts[i]);
 
     setClient(0);
 
     InspectorCounters::decrementCounter(InspectorCounters::DocumentCounter);
 }
@@ skipping 5096 matching lines @@
     visitor->trace(m_contextFeatures);
     visitor->trace(m_userActionElements);
     visitor->registerWeakMembers<Document, &Document::clearWeakMembers>(this);
     DocumentSupplementable::trace(visitor);
     TreeScope::trace(visitor);
     ContainerNode::trace(visitor);
     ExecutionContext::trace(visitor);
 }
 
 } // namespace WebCore