Remove some unused functions in core

Source/core/layout/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/layout/style/LayoutStyleConstants.h"
 
 namespace blink {
 
 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 isSimpleUnderline() const { return m_line == TextDecorationUnderline && m_style == TextDecorationStyleSolid && m_color.isCurrentColor(); }
     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 blink
 
 #endif // AppliedTextDecoration_h