Oilpan: prevent eager tracing of Node and RenderObjects.

Source/core/rendering/RenderObject.h

 /*
  * Copyright (C) 2000 Lars Knoll (knoll@kde.org)
  *           (C) 2000 Antti Koivisto (koivisto@kde.org)
  *           (C) 2000 Dirk Mueller (mueller@kde.org)
  *           (C) 2004 Allan Sandfeld Jensen (kde@carewolf.com)
  * Copyright (C) 2003, 2004, 2005, 2006, 2007, 2008, 2009, 2012 Apple Inc. All rights reserved.
  * Copyright (C) 2009 Google 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
@@ skipping 1387 matching lines @@
     // This stores the paint invalidation rect from the previous frame.
     LayoutRect m_previousPaintInvalidationRect;
 
     // This stores the position in the paint invalidation backing's coordinate.
     // It is used to detect renderer shifts that forces a full invalidation.
     LayoutPoint m_previousPositionFromPaintInvalidationBacking;
 
     static unsigned s_instanceCount;
 };
 
+WILL_NOT_BE_EAGERLY_TRACED_CLASS(RenderObject);
+
 // FIXME: remove this once the render object lifecycle ASSERTS are no longer hit.
 class DeprecatedDisableModifyRenderTreeStructureAsserts {
     WTF_MAKE_NONCOPYABLE(DeprecatedDisableModifyRenderTreeStructureAsserts);
 public:
     DeprecatedDisableModifyRenderTreeStructureAsserts();
 
     static bool canModifyRenderTreeStateInAnyState();
 
 private:
     TemporaryChange<bool> m_disabler;
@@ skipping 199 matching lines @@
 void showTree(const blink::RenderObject*);
 void showLineTree(const blink::RenderObject*);
 void showRenderTree(const blink::RenderObject* object1);
 // We don't make object2 an optional parameter so that showRenderTree
 // can be called from gdb easily.
 void showRenderTree(const blink::RenderObject* object1, const blink::RenderObject* object2);
 
 #endif
 
 #endif // RenderObject_h