BoxBorderPainter should use computed color alpha

Source/core/style/ComputedStyle.cpp

 /*
  * Copyright (C) 1999 Antti Koivisto (koivisto@kde.org)
  * Copyright (C) 2004, 2005, 2006, 2007, 2008, 2009, 2010 Apple Inc. All rights reserved.
  * Copyright (C) 2011 Adobe Systems Incorporated. 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 1697 matching lines @@
     return true;
 }
 
 void ComputedStyle::getBorderEdgeInfo(BorderEdge edges[], bool includeLogicalLeftEdge, bool includeLogicalRightEdge) const
 {
     bool horizontal = isHorizontalWritingMode();
 
     edges[BSTop] = BorderEdge(borderTopWidth(),
         visitedDependentColor(CSSPropertyBorderTopColor),
         borderTopStyle(),
-        borderTopIsTransparent(),
         horizontal || includeLogicalLeftEdge);
 
     edges[BSRight] = BorderEdge(borderRightWidth(),
         visitedDependentColor(CSSPropertyBorderRightColor),
         borderRightStyle(),
-        borderRightIsTransparent(),
         !horizontal || includeLogicalRightEdge);
 
     edges[BSBottom] = BorderEdge(borderBottomWidth(),
         visitedDependentColor(CSSPropertyBorderBottomColor),
         borderBottomStyle(),
-        borderBottomIsTransparent(),
         horizontal || includeLogicalRightEdge);
 
     edges[BSLeft] = BorderEdge(borderLeftWidth(),
         visitedDependentColor(CSSPropertyBorderLeftColor),
         borderLeftStyle(),
-        borderLeftIsTransparent(),
         !horizontal || includeLogicalLeftEdge);
 }
 
 void ComputedStyle::copyChildDependentFlagsFrom(const ComputedStyle& other)
 {
     setEmptyState(other.emptyState());
     if (other.hasExplicitlyInheritedProperties())
         setHasExplicitlyInheritedProperties();
 }
 
 } // namespace blink