Oilpan: move RenderObjects off heap.

Source/core/layout/LayoutTableRow.h

 /*
  * Copyright (C) 1997 Martin Jones (mjones@kde.org)
  *           (C) 1997 Torben Weis (weis@kde.org)
  *           (C) 1998 Waldo Bastian (bastian@kde.org)
  *           (C) 1999 Lars Knoll (knoll@kde.org)
  *           (C) 1999 Antti Koivisto (koivisto@kde.org)
  * Copyright (C) 2003, 2004, 2005, 2006, 2009, 2013 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
@@ skipping 17 matching lines @@
 #include "core/layout/LayoutTableSection.h"
 
 namespace blink {
 
 static const unsigned unsetRowIndex = 0x7FFFFFFF;
 static const unsigned maxRowIndex = 0x7FFFFFFE; // 2,147,483,646
 
 class LayoutTableRow final : public RenderBox {
 public:
     explicit LayoutTableRow(Element*);
-    virtual void trace(Visitor*) override;
 
     LayoutTableCell* firstCell() const;
     LayoutTableCell* lastCell() const;
 
     LayoutTableRow* previousRow() const;
     LayoutTableRow* nextRow() const;
 
     const RenderObjectChildList* children() const { return &m_children; }
     RenderObjectChildList* children() { return &m_children; }
 
@@ skipping 103 matching lines @@
 
 inline LayoutTableRow* LayoutTableSection::lastRow() const
 {
     ASSERT(children() == virtualChildren());
     return toLayoutTableRow(children()->lastChild());
 }
 
 } // namespace blink
 
 #endif // LayoutTableRow_h