Oilpan: make DOMWindowProperty a GC mixin.

Source/core/editing/DOMSelection.h

 /*
  * Copyright (C) 2007 Apple Inc.  All rights reserved.
  * 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:
  *
  * 1.  Redistributions of source code must retain the above copyright
  *     notice, this list of conditions and the following disclaimer.
@@ skipping 30 matching lines @@
 namespace blink {
 
 class ExceptionState;
 class LocalFrame;
 class Node;
 class Position;
 class Range;
 class TreeScope;
 class VisibleSelection;
 
-class DOMSelection FINAL : public RefCountedWillBeGarbageCollectedFinalized<DOMSelection>, public ScriptWrappable, public DOMWindowProperty {
+class DOMSelection FINAL : public RefCountedWillBeGarbageCollected<DOMSelection>, public ScriptWrappable, public DOMWindowProperty {
     DEFINE_WRAPPERTYPEINFO();
+    WILL_BE_USING_GARBAGE_COLLECTED_MIXIN(DOMSelection);
 public:
     static PassRefPtrWillBeRawPtr<DOMSelection> create(const TreeScope* treeScope)
     {
         return adoptRefWillBeNoop(new DOMSelection(treeScope));
     }
 
     void clearTreeScope();
 
     // Safari Selection Object API
     // These methods return the valid equivalents of internal editing positions.
@@ skipping 26 matching lines @@
     void addRange(Range*);
     void deleteFromDocument();
     bool containsNode(const Node*, bool partlyContained) const;
     void selectAllChildren(Node*, ExceptionState&);
 
     String toString();
 
     // Microsoft Selection Object API
     void empty();
 
-    void trace(Visitor* visitor) { visitor->trace(m_treeScope); }
+    virtual void trace(Visitor*) OVERRIDE;
 
 private:
     explicit DOMSelection(const TreeScope*);
 
     // Convenience method for accessors, does not check m_frame present.
     const VisibleSelection& visibleSelection() const;
 
     Node* shadowAdjustedNode(const Position&) const;
     int shadowAdjustedOffset(const Position&) const;
 
     bool isValidForPosition(Node*) const;
 
     void addConsoleError(const String& message);
 
     RawPtrWillBeMember<const TreeScope> m_treeScope;
 };
 
 } // namespace blink
 
 #endif // DOMSelection_h