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

Source/core/rendering/RenderView.cpp

 /*
  * Copyright (C) 1999 Lars Knoll (knoll@kde.org)
  * Copyright (C) 2004, 2005, 2006, 2007, 2008, 2009 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
  * License as published by the Free Software Foundation; either
  * version 2 of the License, or (at your option) any later version.
  *
  * This library is distributed in the hope that it will be useful,
@@ skipping 224 matching lines @@
 
     // Do one last layout that should update the auto-height regions found in the main flow
     // and solve pathological dependencies between regions (e.g. a non-auto-height region depending
     // on an auto-height one).
     if (needsLayout())
         layoutContent(state);
 }
 
 void RenderView::layout()
 {
-    StackStats::LayoutCheckPoint layoutCheckPoint;
     if (!document()->paginated())
         setPageLogicalHeight(0);
 
     if (shouldUsePrintingLayout())
         m_minPreferredLogicalWidth = m_maxPreferredLogicalWidth = logicalWidth();
 
     SubtreeLayoutScope layoutScope(this);
 
     // Use calcWidth/Height to get the new width/height, since this will take the full page zoom factor into account.
     bool relayoutChildren = !shouldUsePrintingLayout() && (!m_frameView || width() != viewWidth() || height() != viewHeight());
@@ skipping 897 matching lines @@
 #endif
 
     if (layoutState)
         layoutState->m_isPaginated = m_fragmenting;
 
     if (m_flowThreadState != RenderObject::NotInsideFlowThread)
         m_root->setFlowThreadStateIncludingDescendants(m_flowThreadState);
 }
 
 } // namespace WebCore