Remove gfx::DIAGONAL_STRIKE and supporting code.

ui/gfx/render_text_mac.h

 // Copyright (c) 2012 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_RENDER_TEXT_MAC_H_
 #define UI_GFX_RENDER_TEXT_MAC_H_
 
 #include <ApplicationServices/ApplicationServices.h>
 #include <stddef.h>
 #include <stdint.h>
@@ skipping 56 matching lines @@
     CTRunRef ct_run;
     SkPoint origin;
     std::vector<uint16_t> glyphs;
     std::vector<SkPoint> glyph_positions;
     SkScalar width;
     base::ScopedCFTypeRef<CTFontRef> ct_font;
     sk_sp<SkTypeface> typeface;
     SkColor foreground;
     bool underline;
     bool strike;
-    bool diagonal_strike;
 
     TextRun();
     TextRun(const TextRun& other) = delete;
     TextRun(TextRun&& other);
     ~TextRun();
   };
 
   // Returns the width used to draw |layout_text_|.
   float GetLayoutTextWidth();
 
@@ skipping 45 matching lines @@
 
   // Indicates that |runs_| are valid, set by |ComputeRuns()|.
   bool runs_valid_;
 
   DISALLOW_COPY_AND_ASSIGN(RenderTextMac);
 };
 
 }  // namespace gfx
 
 #endif  // UI_GFX_RENDER_TEXT_MAC_H_