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

Source/core/rendering/svg/RenderSVGHiddenContainer.cpp

 /*
  * Copyright (C) 2007 Eric Seidel <eric@webkit.org>
  *
  * 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,
  * but WITHOUT ANY WARRANTY; without even the implied warranty of
@@ skipping 12 matching lines @@
 
 namespace WebCore {
 
 RenderSVGHiddenContainer::RenderSVGHiddenContainer(SVGElement* element)
     : RenderSVGContainer(element)
 {
 }
 
 void RenderSVGHiddenContainer::layout()
 {
-    StackStats::LayoutCheckPoint layoutCheckPoint;
     ASSERT(needsLayout());
     SVGRenderSupport::layoutChildren(this, selfNeedsLayout());
     clearNeedsLayout();
 }
 
 void RenderSVGHiddenContainer::paint(PaintInfo&, const LayoutPoint&)
 {
     // This subtree does not paint.
 }
 
 void RenderSVGHiddenContainer::absoluteQuads(Vector<FloatQuad>&, bool*) const
 {
     // This subtree does not take up space or paint
 }
 
 bool RenderSVGHiddenContainer::nodeAtFloatPoint(const HitTestRequest&, HitTestResult&, const FloatPoint&, HitTestAction)
 {
     return false;
 }
 
 }