Remove gfx::DIAGONAL_STRIKE and supporting code.

ui/gfx/decorated_text.h

 // Copyright 2016 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 UI_GFX_DECORATED_TEXT_H_
 #define UI_GFX_DECORATED_TEXT_H_
 
 #include <vector>
 
 #include "base/strings/string16.h"
@@ skipping 10 matching lines @@
   struct GFX_EXPORT RangedAttribute {
     // Disallow default construction of Font, since that's slow.
     RangedAttribute() = delete;
     RangedAttribute(const Range& range, const Font& font);
 
     // The range in |text|, this RangedAttribute corresponds to. Should not be
     // reversed and should lie within the bounds of |text|.
     Range range;
     Font font;
     bool strike;
-    bool diagonal_strike;
   };
 
   DecoratedText();
   ~DecoratedText();
 
   base::string16 text;
 
   // Vector of RangedAttribute describing styling of non-overlapping ranges
   // in |text|.
   std::vector<RangedAttribute> attributes;
 };
 
 };  // namespace gfx
 
 #endif  // UI_GFX_DECORATED_TEXT_H_