Oilpan: Make the Node hierarchy RefCountedGarbageCollected instead of TreeShared.

Source/core/dom/shadow/ElementShadow.h

 /*
  * 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.
  *     * Neither the name of Google Inc. nor the names of its
@@ skipping 21 matching lines @@
 #include "core/dom/shadow/ShadowRoot.h"
 #include "wtf/DoublyLinkedList.h"
 #include "wtf/Forward.h"
 #include "wtf/HashMap.h"
 #include "wtf/Noncopyable.h"
 #include "wtf/PassOwnPtr.h"
 #include "wtf/Vector.h"
 
 namespace WebCore {
 
-class ElementShadow {
+class ElementShadow FINAL {
     WTF_MAKE_NONCOPYABLE(ElementShadow); WTF_MAKE_FAST_ALLOCATED;
 public:
     static PassOwnPtr<ElementShadow> create();
     ~ElementShadow();
 
     Element* host() const;
     ShadowRoot* youngestShadowRoot() const { return m_shadowRoots.head(); }
     ShadowRoot* oldestShadowRoot() const { return m_shadowRoots.tail(); }
     ElementShadow* containingShadow() const;
 
     ShadowRoot& addShadowRoot(Element& shadowHost, ShadowRoot::ShadowRootType);
 
     bool hasSameStyles(const ElementShadow*) const;
 
     void attach(const Node::AttachContext&);
     void detach(const Node::AttachContext&);
 
     void didAffectSelector(AffectedSelectorMask);
     void willAffectSelector();
     const SelectRuleFeatureSet& ensureSelectFeatureSet();
 
     void distributeIfNeeded();
     void setNeedsDistributionRecalc();
 
     const InsertionPoint* finalDestinationInsertionPointFor(const Node*) const;
     const DestinationInsertionPoints* destinationInsertionPointsFor(const Node*) const;
 
     void didDistributeNode(const Node*, InsertionPoint*);
 
+    void trace(Visitor*);
+
 private:
     ElementShadow();
 
     void removeDetachedShadowRoots();
 
     void distribute();
     void clearDistribution();
 
     void collectSelectFeatureSetFrom(ShadowRoot&);
     void distributeNodeChildrenTo(InsertionPoint*, ContainerNode*);
@@ skipping 40 matching lines @@
 inline void ElementShadow::distributeIfNeeded()
 {
     if (m_needsDistributionRecalc)
         distribute();
     m_needsDistributionRecalc = false;
 }
 
 } // namespace
 
 #endif