Skip overflow adjustment checks when possible in StyleAdjuster

Source/core/css/resolver/StyleAdjuster.h

 /*
  * Copyright (C) 2013 Google, Inc.
  * Copyright (C) 1999 Lars Knoll (knoll@kde.org)
  * Copyright (C) 2003, 2004, 2005, 2006, 2007, 2008, 2009, 2010, 2011 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.
  *
@@ skipping 25 matching lines @@
     StyleAdjuster(const CachedUAStyle& cachedUAStyle, bool useQuirksModeStyles)
         : m_cachedUAStyle(cachedUAStyle)
         , m_useQuirksModeStyles(useQuirksModeStyles)
     { }
 
     void adjustRenderStyle(RenderStyle* styleToAdjust, RenderStyle* parentStyle, Element*);
 
 private:
     void adjustStyleForDisplay(RenderStyle* styleToAdjust, RenderStyle* parentStyle);
     void adjustStyleForTagName(RenderStyle* styleToAdjust, RenderStyle* parentStyle, Element&);
+    void adjustOverflow(RenderStyle* styleToAdjust, Element*);
 
     const CachedUAStyle& m_cachedUAStyle;
     bool m_useQuirksModeStyles;
 };
 
 } // namespace WebCore
 
 #endif // StyleAdjuster_h