Don't render border images when border-style is none

third_party/WebKit/Source/core/style/BorderValue.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 @@
 public:
     BorderValue()
         : m_color(0)
         , m_colorIsCurrentColor(true)
         , m_width(3)
         , m_style(BNONE)
         , m_isAuto(AUTO_OFF)
     {
     }
 
-    bool nonZero(bool checkStyle = true) const
+    bool nonZero() const
     {
-        return width() && (!checkStyle || m_style != BNONE);
+        return width() && (m_style != BNONE);
     }
 
     bool isTransparent() const
     {
         return !m_colorIsCurrentColor && !m_color.alpha();
     }
 
-    bool isVisible(bool checkStyle = true) const
+    bool isVisible() const
     {
-        return nonZero(checkStyle) && !isTransparent() && (!checkStyle || m_style != BHIDDEN);
+        return nonZero() && !isTransparent() && (m_style != BHIDDEN);
     }
 
     bool operator==(const BorderValue& o) const
     {
         return m_width == o.m_width && m_style == o.m_style && m_color == o.m_color && m_colorIsCurrentColor == o.m_colorIsCurrentColor;
     }
 
     // The default width is 3px, but if the style is none we compute a value of 0 (in ComputedStyle itself)
     bool visuallyEqual(const BorderValue& o) const
     {
@@ skipping 29 matching lines @@
     unsigned m_width : 26;
     unsigned m_style : 4; // EBorderStyle
 
     // This is only used by OutlineValue but moved here to keep the bits packed.
     unsigned m_isAuto : 1; // OutlineIsAuto
 };
 
 } // namespace blink
 
 #endif // BorderValue_h