Fix incorrect style recalculation of text-decoration properties.

Source/core/rendering/style/AppliedTextDecoration.h

 // Copyright 2014 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #ifndef AppliedTextDecoration_h
 #define AppliedTextDecoration_h
 
+#include "core/css/StyleColor.h"
 #include "core/rendering/style/RenderStyleConstants.h"
 
 namespace WebCore {
 
 class AppliedTextDecoration {
 public:
+    AppliedTextDecoration(TextDecoration, TextDecorationStyle, StyleColor);
     explicit AppliedTextDecoration(TextDecoration);
     AppliedTextDecoration();
 
     TextDecoration line() const { return static_cast<TextDecoration>(m_line); }
+    TextDecorationStyle style() const { return static_cast<TextDecorationStyle>(m_style); }
 
+    bool isSimple() const { return m_style == TextDecorationStyleSolid && m_color.isCurrentColor(); }

[Julien - ping for review, 2014/05/19 10:30:18]

We should disambiguate this function: it only makes sense on Underline so we
should make this clear by changing the name to isSimpleUnderline(). Furthermore
we either enforce the assumption via an ASSERT or just add the appropriate text
decoration check. I prefer the second option but could live with the first.

[andersr, 2014/05/19 12:54:02]

Done.

     bool operator==(const AppliedTextDecoration&) const;
     bool operator!=(const AppliedTextDecoration& o) const { return !(*this == o); }
 
 private:
     unsigned m_line : TextDecorationBits;
+    unsigned m_style : 3; // TextDecorationStyle
+    StyleColor m_color;
 };
 
 } // namespace WebCore
 
 #endif // AppliedTextDecoration_h