Oilpan: Make the Node hierarchy RefCountedGarbageCollected instead of TreeShared.

Source/core/dom/TreeScope.h

 /*
  * Copyright (C) 2011 Google Inc. All Rights Reserved.
  * Copyright (C) 2012 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
@@ skipping 80 matching lines @@
     // for an anchor with the given name. ID matching is always case sensitive, but
     // Anchor name matching is case sensitive in strict mode and not case sensitive in
     // quirks mode for historical compatibility reasons.
     Element* findAnchor(const String& name);
 
     bool applyAuthorStyles() const;
 
     // Used by the basic DOM mutation methods (e.g., appendChild()).
     void adoptIfNeeded(Node&);
 
-    Node& rootNode() const { return m_rootNode; }
+    Node& rootNode() const { return *m_rootNode; }
 
     IdTargetObserverRegistry& idTargetObserverRegistry() const { return *m_idTargetObserverRegistry.get(); }
 
 
 #if !ENABLE(OILPAN)
     // Nodes belonging to this scope hold guard references -
     // these are enough to keep the scope from being destroyed, but
     // not enough to keep it from removing its children. This allows a
     // node that outlives its scope to still have a valid document
     // pointer without introducing reference cycles.
@@ skipping 38 matching lines @@
 
 #if !ENABLE(OILPAN)
     bool hasGuardRefCount() const { return m_guardRefCount; }
 #endif
 
     void setNeedsStyleRecalcForViewportUnits();
 
 private:
     virtual void dispose() { }
 
+#if !ENABLE(OILPAN)
     int refCount() const;
-#if SECURITY_ASSERT_ENABLED
+#endif
+
+#if SECURITY_ASSERT_ENABLED && !ENABLE(OILPAN)
     bool deletionHasBegun();
     void beginDeletion();
 #else
     bool deletionHasBegun() { return false; }
     void beginDeletion() { }
 #endif
 
     bool rootNodeHasTreeSharedParent() const;
 
-    Node& m_rootNode;
-    Document* m_document;
+    RawPtrWillBeMember<Node> m_rootNode;
+    RawPtrWillBeMember<Document> m_document;
     RawPtrWillBeMember<TreeScope> m_parentTreeScope;
 
 #if !ENABLE(OILPAN)
     int m_guardRefCount;
 #endif
 
     OwnPtr<DocumentOrderedMap> m_elementsById;
     OwnPtr<DocumentOrderedMap> m_imageMapsByName;
     OwnPtr<DocumentOrderedMap> m_labelsByForAttribute;
 
@@ skipping 19 matching lines @@
 inline bool operator!=(const TreeScope& a, const TreeScope& b) { return !(a == b); }
 inline bool operator!=(const TreeScope& a, const TreeScope* b) { return !(a == b); }
 inline bool operator!=(const TreeScope* a, const TreeScope& b) { return !(a == b); }
 
 HitTestResult hitTestInDocument(const Document*, int x, int y);
 TreeScope* commonTreeScope(Node*, Node*);
 
 } // namespace WebCore
 
 #endif // TreeScope_h