BoxBorderPainter should use computed color alpha

Source/core/style/ComputedStyle.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 488 matching lines @@
     const BorderImageLengthBox& borderImageOutset() const { return surround->border.image().outset(); }
 
     const LengthSize& borderTopLeftRadius() const { return surround->border.topLeft(); }
     const LengthSize& borderTopRightRadius() const { return surround->border.topRight(); }
     const LengthSize& borderBottomLeftRadius() const { return surround->border.bottomLeft(); }
     const LengthSize& borderBottomRightRadius() const { return surround->border.bottomRight(); }
     bool hasBorderRadius() const { return surround->border.hasBorderRadius(); }
 
     unsigned borderLeftWidth() const { return surround->border.borderLeftWidth(); }
     EBorderStyle borderLeftStyle() const { return surround->border.left().style(); }
-    bool borderLeftIsTransparent() const { return surround->border.left().isTransparent(); }
     unsigned borderRightWidth() const { return surround->border.borderRightWidth(); }
     EBorderStyle borderRightStyle() const { return surround->border.right().style(); }
-    bool borderRightIsTransparent() const { return surround->border.right().isTransparent(); }
     unsigned borderTopWidth() const { return surround->border.borderTopWidth(); }
     EBorderStyle borderTopStyle() const { return surround->border.top().style(); }
-    bool borderTopIsTransparent() const { return surround->border.top().isTransparent(); }
     unsigned borderBottomWidth() const { return surround->border.borderBottomWidth(); }
     EBorderStyle borderBottomStyle() const { return surround->border.bottom().style(); }
-    bool borderBottomIsTransparent() const { return surround->border.bottom().isTransparent(); }
 
     unsigned short borderBeforeWidth() const;
     unsigned short borderAfterWidth() const;
     unsigned short borderStartWidth() const;
     unsigned short borderEndWidth() const;
 
     unsigned short outlineSize() const { return max(0, outlineWidth() + outlineOffset()); }
     unsigned short outlineWidth() const
     {
         if (m_background->outline().style() == BNONE)
@@ skipping 1388 matching lines @@
 }
 
 inline bool ComputedStyle::hasPseudoElementStyle() const
 {
     return noninherited_flags.pseudoBits & PSEUDO_ELEMENT_MASK;
 }
 
 } // namespace blink
 
 #endif // ComputedStyle_h