Implement font fallback in RenderTextWin, try #2.

ui/gfx/render_text_win.h

 // Copyright (c) 2011 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_
 #pragma once
 
 #include <usp10.h>
 
 #include <vector>
 
 #include "base/memory/scoped_ptr.h"
 #include "ui/gfx/render_text.h"
 
 namespace gfx {
 
 namespace internal {
 
 struct TextRun {
   TextRun();
+  ~TextRun();
 
   ui::Range range;
   Font font;
   // TODO(msw): Disambiguate color, strike, etc. from TextRuns.
   //            Otherwise, this breaks the glyph shaping process.
   //            See the example at: http://www.catch22.net/tuts/neatpad/12.
   SkColor foreground;
   bool strike;
   bool underline;
 
   int width;
   // The cumulative widths of preceding runs.
   int preceding_run_widths;
 
   SCRIPT_ANALYSIS script_analysis;
 
   scoped_array<WORD> glyphs;
   scoped_array<WORD> logical_clusters;
   scoped_array<SCRIPT_VISATTR> visible_attributes;
   int glyph_count;
 
   scoped_array<int> advance_widths;
   scoped_array<GOFFSET> offsets;
   ABC abc_widths;
+  SCRIPT_CACHE script_cache;
 
  private:
   DISALLOW_COPY_AND_ASSIGN(TextRun);
 };
 
 }  // namespace internal
 
 // RenderTextWin is the Windows implementation of RenderText using Uniscribe.
 class RenderTextWin : public RenderText {
  public:
@@ skipping 26 matching lines @@
   void LayoutVisualText();
 
   // Return the run index that contains the argument; or the length of the
   // |runs_| vector if argument exceeds the text length or width.
   size_t GetRunContainingPosition(size_t position) const;
   size_t GetRunContainingPoint(const Point& point) const;
 
   // Given a |run|, returns the SelectionModel that contains the logical first
   // or last caret position inside (not at a boundary of) the run.
   // The returned value represents a cursor/caret position without a selection.
-  SelectionModel FirstSelectionModelInsideRun(internal::TextRun*);
-  SelectionModel LastSelectionModelInsideRun(internal::TextRun*);
+  SelectionModel FirstSelectionModelInsideRun(internal::TextRun* run);
+  SelectionModel LastSelectionModelInsideRun(internal::TextRun* run);
 
   // Get the selection model visually left/right of |selection| by one grapheme.
   // The returned value represents a cursor/caret position without a selection.
   SelectionModel LeftSelectionModel(const SelectionModel& selection);
   SelectionModel RightSelectionModel(const SelectionModel& selection);
 
   // Draw the text, cursor, and selection.
   void DrawSelection(Canvas* canvas);
   void DrawVisualText(Canvas* canvas);
   void DrawCursor(Canvas* canvas);
 
-  bool text_is_dirty_;
-  bool style_is_dirty_;
-
   // National Language Support native digit and digit substitution settings.
   SCRIPT_DIGITSUBSTITUTE digit_substitute_;
 
   SCRIPT_CONTROL script_control_;
   SCRIPT_STATE script_state_;
 
-  SCRIPT_CACHE script_cache_;
-
   std::vector<internal::TextRun*> runs_;
   int string_width_;
 
   scoped_array<int> visual_to_logical_;
   scoped_array<int> logical_to_visual_;
 
   DISALLOW_COPY_AND_ASSIGN(RenderTextWin);
 };
 
 }  // namespace gfx
 
 #endif  // UI_GFX_RENDER_TEXT_WIN_H_