Don't split text runs on underline style change

ui/gfx/render_text_win.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_WIN_H_
 #define UI_GFX_RENDER_TEXT_WIN_H_
 
 #include <usp10.h>
 
 #include <map>
@@ skipping 14 matching lines @@
 
   Range range;
   Font font;
   // A gfx::Font::FontStyle flag to specify bold and italic styles.
   // Supersedes |font.GetFontStyle()|. Stored separately to avoid calling
   // |font.DeriveFont()|, which is expensive on Windows.
   int font_style;
 
   bool strike;
   bool diagonal_strike;
-  bool underline;
 
   int width;
   // The cumulative widths of preceding runs.
   int preceding_run_widths;
 
   SCRIPT_ANALYSIS script_analysis;
 
   scoped_ptr<WORD[]> glyphs;
   scoped_ptr<WORD[]> logical_clusters;
   scoped_ptr<SCRIPT_VISATTR[]> visible_attributes;
@@ skipping 89 matching lines @@
   scoped_ptr<int[]> logical_to_visual_;
 
   bool needs_layout_;
 
   DISALLOW_COPY_AND_ASSIGN(RenderTextWin);
 };
 
 }  // namespace gfx
 
 #endif  // UI_GFX_RENDER_TEXT_WIN_H_