Avoid leaking ThreadingPrimitives.h from StackStats.h when collection is off.

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 39 matching lines @@
 {
 }
 
 HTMLMediaElement* RenderMedia::mediaElement() const
 {
     return toHTMLMediaElement(node());
 }
 
 void RenderMedia::layout()
 {
-    StackStats::LayoutCheckPoint layoutCheckPoint;
     LayoutSize oldSize = contentBoxRect().size();
 
     RenderImage::layout();
 
     RenderBox* controlsRenderer = toRenderBox(m_children.firstChild());
     if (!controlsRenderer)
         return;
 
     bool controlsNeedLayout = controlsRenderer->needsLayout();
     // If the region chain has changed we also need to relayout the controls to update the region box info.
@@ skipping 20 matching lines @@
     clearNeedsLayout();
 
     statePusher.pop();
 }
 
 void RenderMedia::paintReplaced(PaintInfo&, const LayoutPoint&)
 {
 }
 
 } // namespace WebCore