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

Source/core/rendering/RenderListMarker.cpp

 /*
  * Copyright (C) 1999 Lars Knoll (knoll@kde.org)
  *           (C) 1999 Antti Koivisto (koivisto@kde.org)
  * Copyright (C) 2003, 2004, 2005, 2006, 2007, 2008 Apple Inc. All rights reserved.
  * Copyright (C) 2006 Andrew Wellington (proton@wiretapped.net)
  * Copyright (C) 2010 Daniel Bates (dbates@intudata.com)
  *
  * 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
@@ skipping 1303 matching lines @@
             suffixRunInfo.bounds = marker;
             context->drawText(font, suffixRunInfo, textOrigin);
 
             context->drawText(font, textRunPaintInfo, textOrigin + IntSize(font.width(suffixRun), 0));
         }
     }
 }
 
 void RenderListMarker::layout()
 {
-    StackStats::LayoutCheckPoint layoutCheckPoint;
     ASSERT(needsLayout());
 
     if (isImage()) {
         updateMarginsAndContent();
         setWidth(m_image->imageSize(this, style()->effectiveZoom()).width());
         setHeight(m_image->imageSize(this, style()->effectiveZoom()).height());
     } else {
         setLogicalWidth(minPreferredLogicalWidth());
         setLogicalHeight(style()->fontMetrics().height());
     }
@@ skipping 506 matching lines @@
 
     if (clipToVisibleContent)
         computeRectForRepaint(repaintContainer, rect);
     else
         rect = localToContainerQuad(FloatRect(rect), repaintContainer).enclosingBoundingBox();
 
     return rect;
 }
 
 } // namespace WebCore