Don't repaint when setting border or outline 0 with style none

Source/core/rendering/style/StyleBackgroundData.h

 /*
  * Copyright (C) 2000 Lars Knoll (knoll@kde.org)
  *           (C) 2000 Antti Koivisto (koivisto@kde.org)
  *           (C) 2000 Dirk Mueller (mueller@kde.org)
  * Copyright (C) 2003, 2005, 2006, 2007, 2008 Apple Inc. All rights reserved.
  * Copyright (C) 2006 Graham Dennis (graham.dennis@gmail.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 27 matching lines @@
     static PassRefPtr<StyleBackgroundData> create() { return adoptRef(new StyleBackgroundData); }
     PassRefPtr<StyleBackgroundData> copy() const { return adoptRef(new StyleBackgroundData(*this)); }
     ~StyleBackgroundData() { }
 
     bool operator==(const StyleBackgroundData& o) const;
     bool operator!=(const StyleBackgroundData& o) const
     {
         return !(*this == o);
     }
 
+    bool visuallyEqual(const StyleBackgroundData&) const;
+
     const FillLayer& background() const { return m_background; }
     const StyleColor& color() const { return m_color; }
     const OutlineValue& outline() const { return m_outline; }
 
 private:
     friend class RenderStyle;
 
     StyleBackgroundData();
     StyleBackgroundData(const StyleBackgroundData&);
 
     FillLayer m_background;
     StyleColor m_color;
     OutlineValue m_outline;
 };
 
 } // namespace WebCore
 
 #endif // StyleBackgroundData_h