Factor painting code out of RenderBox into a new class called BoxPainter.

Source/core/rendering/style/RenderStyle.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, 2009, 2010, 2011 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 82 matching lines @@
         group.access()->variable.setColor(value)
 
 namespace blink {
 
 using std::max;
 
 class FilterOperations;
 
 class AppliedTextDecoration;
 class BorderData;
+class BorderEdge;
 class CounterContent;
 class Font;
 class FontMetrics;
 class ShadowList;
 class StyleImage;
 class StyleInheritedData;
 class StyleResolver;
 class TransformationMatrix;
 
 class ContentData;
@@ skipping 1422 matching lines @@
     Color visitedDependentColor(int colorProperty) const;
 
     void setHasExplicitlyInheritedProperties() { noninherited_flags.explicitInheritance = true; }
     bool hasExplicitlyInheritedProperties() const { return noninherited_flags.explicitInheritance; }
 
     void setHasCurrentColor() { noninherited_flags.currentColor = true; }
     bool hasCurrentColor() const { return noninherited_flags.currentColor; }
 
     bool hasBoxDecorations() const { return hasBorder() || hasBorderRadius() || hasOutline() || hasAppearance() || boxShadow() || hasFilter(); }
 
+    bool borderObscuresBackground() const;
+    void getBorderEdgeInfo(BorderEdge edges[], bool includeLogicalLeftEdge = true, bool includeLogicalRightEdge = true) const;
+
     // Initial values for all the properties
     static EBorderCollapse initialBorderCollapse() { return BSEPARATE; }
     static EBorderStyle initialBorderStyle() { return BNONE; }
     static OutlineIsAuto initialOutlineStyleIsAuto() { return AUTO_OFF; }
     static NinePieceImage initialNinePieceImage() { return NinePieceImage(); }
     static LengthSize initialBorderRadius() { return LengthSize(Length(0, Fixed), Length(0, Fixed)); }
     static ECaptionSide initialCaptionSide() { return CAPTOP; }
     static EClear initialClear() { return CNONE; }
     static LengthBox initialClip() { return LengthBox(); }
     static TextDirection initialDirection() { return LTR; }
@@ skipping 361 matching lines @@
 inline bool RenderStyle::hasPseudoElementStyle() const
 {
     return noninherited_flags.pseudoBits & PSEUDO_ELEMENT_MASK;
 }
 
 float calcBorderRadiiConstraintScaleFor(const FloatRect&, const FloatRoundedRect::Radii&);
 
 } // namespace blink
 
 #endif // RenderStyle_h