Oilpan: move RenderObjects off heap.

Source/core/rendering/RenderMedia.cpp

 /*
  * Copyright (C) 2007, 2008, 2009, 2010 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
  *    notice, this list of conditions and the following disclaimer in the
@@ skipping 24 matching lines @@
 RenderMedia::RenderMedia(HTMLMediaElement* video)
     : RenderImage(video)
 {
     setImageResource(RenderImageResource::create());
 }
 
 RenderMedia::~RenderMedia()
 {
 }
 
-void RenderMedia::trace(Visitor* visitor)
-{
-    visitor->trace(m_children);
-    RenderImage::trace(visitor);
-}
-
 HTMLMediaElement* RenderMedia::mediaElement() const
 {
     return toHTMLMediaElement(node());
 }
 
 void RenderMedia::layout()
 {
     LayoutSize oldSize = contentBoxRect().size();
 
     RenderImage::layout();
@@ skipping 24 matching lines @@
     // child of replaced content, which is not supposed to be possible. This
     // check can be removed if ::-webkit-media-controls is made internal.
     return child->isFlexibleBox();
 }
 
 void RenderMedia::paintReplaced(const PaintInfo&, const LayoutPoint&)
 {
 }
 
 } // namespace blink