Oilpan: Prepare to move RenderObject and RenderObjectChildList to Oilpan heap.

Source/core/rendering/RenderListItem.h

 /*
  * Copyright (C) 1999 Lars Knoll (knoll@kde.org)
  *           (C) 1999 Antti Koivisto (koivisto@kde.org)
  * Copyright (C) 2003, 2004, 2005, 2006, 2007, 2009 Apple Inc. All rights reserved.
  *
  * This library is free software; you can redistribute it and/or
  * modify it under the terms of the GNU Library General Public
  * License as published by the Free Software Foundation; either
  * version 2 of the License, or (at your option) any later version.
  *
@@ skipping 15 matching lines @@
 #include "core/rendering/RenderBlockFlow.h"
 
 namespace blink {
 
 class HTMLOListElement;
 class RenderListMarker;
 
 class RenderListItem FINAL : public RenderBlockFlow {
 public:
     explicit RenderListItem(Element*);
+    virtual void trace(Visitor*) OVERRIDE;
 
     int value() const { if (!m_isValueUpToDate) updateValueNow(); return m_value; }
     void updateValue();
 
     bool hasExplicitValue() const { return m_hasExplicitValue; }
     int explicitValue() const { return m_explicitValue; }
     void setExplicitValue(int value);
     void clearExplicitValue();
 
     void setNotInList(bool);
@@ skipping 30 matching lines @@
 
     virtual void styleDidChange(StyleDifference, const RenderStyle* oldStyle) OVERRIDE;
 
     virtual void addOverflowFromChildren() OVERRIDE;
 
     inline int calcValue() const;
     void updateValueNow() const;
     void explicitValueChanged();
 
     int m_explicitValue;
-    RenderListMarker* m_marker;
+    RawPtrWillBeMember<RenderListMarker> m_marker;
     mutable int m_value;
 
     bool m_hasExplicitValue : 1;
     mutable bool m_isValueUpToDate : 1;
     bool m_notInList : 1;
 };
 
 DEFINE_RENDER_OBJECT_TYPE_CASTS(RenderListItem, isListItem());
 
 } // namespace blink
 
 #endif // RenderListItem_h