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

Source/core/rendering/RenderTextControlSingleLine.cpp

 /**
  * Copyright (C) 2006, 2007, 2010 Apple Inc. All rights reserved.
  *           (C) 2008 Torch Mobile Inc. All rights reserved. (http://www.torchmobile.com/)
  * Copyright (C) 2010 Google Inc. All rights reserved.
  * Copyright (C) 2010 Nokia Corporation and/or its subsidiary(-ies).
  *
  * 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 72 matching lines @@
     }
 }
 
 LayoutUnit RenderTextControlSingleLine::computeLogicalHeightLimit() const
 {
     return containerElement() ? contentLogicalHeight() : logicalHeight();
 }
 
 void RenderTextControlSingleLine::layout()
 {
-    StackStats::LayoutCheckPoint layoutCheckPoint;
     SubtreeLayoutScope layoutScope(this);
 
     // FIXME: We should remove the height-related hacks in layout() and
     // styleDidChange(). We need them because
     // - Center the inner elements vertically if the input height is taller than
     //   the intrinsic height of the inner elements.
     // - Shrink the inner elment heights if the input height is samller than the
     //   intrinsic heights of the inner elements.
 
     // We don't honor paddings and borders for textfields without decorations
@@ skipping 321 matching lines @@
     if (innerTextElement())
         innerTextElement()->setScrollTop(newTop);
 }
 
 HTMLInputElement* RenderTextControlSingleLine::inputElement() const
 {
     return toHTMLInputElement(node());
 }
 
 }