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

Source/core/rendering/RenderReplaced.cpp

 /*
  * Copyright (C) 1999 Lars Knoll (knoll@kde.org)
  * Copyright (C) 2000 Dirk Mueller (mueller@kde.org)
  * Copyright (C) 2004, 2006, 2007 Apple Inc. All rights reserved.
  * Copyright (C) Research In Motion Limited 2011-2012. 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
  * License as published by the Free Software Foundation; either
  * version 2 of the License, or (at your option) any later version.
@@ skipping 57 matching lines @@
     RenderBox::styleDidChange(diff, oldStyle);
 
     bool hadStyle = (oldStyle != 0);
     float oldZoom = hadStyle ? oldStyle->effectiveZoom() : RenderStyle::initialZoom();
     if (style() && style()->effectiveZoom() != oldZoom)
         intrinsicSizeChanged();
 }
 
 void RenderReplaced::layout()
 {
-    StackStats::LayoutCheckPoint layoutCheckPoint;
     ASSERT(needsLayout());
 
     LayoutRepainter repainter(*this, checkForRepaintDuringLayout());
 
     setHeight(minimumReplacedHeight());
 
     updateLogicalWidth();
     updateLogicalHeight();
 
     m_overflow.clear();
@@ skipping 521 matching lines @@
 
     if (style()) {
         if (v)
             r.inflate(style()->outlineSize());
     }
     computeRectForRepaint(repaintContainer, r);
     return r;
 }
 
 }