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

Source/core/rendering/RenderVideo.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 182 matching lines @@
         mediaPlayer->paintCurrentFrameInContext(context, pixelSnappedIntRect(rect));
     else
         mediaPlayer->paint(context, pixelSnappedIntRect(rect));
 
     if (clip)
         context->restore();
 }
 
 void RenderVideo::layout()
 {
-    StackStats::LayoutCheckPoint layoutCheckPoint;
     RenderMedia::layout();
     updatePlayer();
 }
 
 HTMLVideoElement* RenderVideo::videoElement() const
 {
     ASSERT(isHTMLVideoElement(node()));
     return toHTMLVideoElement(node());
 }
 
@@ skipping 76 matching lines @@
 }
 
 LayoutUnit RenderVideo::offsetHeight() const
 {
     if (const RenderBlock* block = rendererPlaceholder(this))
         return block->offsetHeight();
     return RenderMedia::offsetHeight();
 }
 
 } // namespace WebCore