Always try metafile font fallback in the case of missing glyphs in RenderTextWin.

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_
 #pragma once
 
 #include <usp10.h>
 
@@ skipping 77 matching lines @@
   virtual std::vector<Rect> GetSubstringBounds(ui::Range range) OVERRIDE;
   virtual bool IsCursorablePosition(size_t position) OVERRIDE;
   virtual void ResetLayout() OVERRIDE;
   virtual void EnsureLayout() OVERRIDE;
   virtual void DrawVisualText(Canvas* canvas) OVERRIDE;
 
  private:
   void ItemizeLogicalText();
   void LayoutVisualText();
 
+  // Helper function to update the font on a text run after font substitution.
+  void UpdateRunFont(internal::TextRun* run, int font_size);

[msw, 2012/04/12 21:32:14]

nit: Consider renaming this ApplyFontSubstitute or similar.

[Alexei Svitkine (slow), 2012/04/13 13:56:15]

Done.

+
   // Returns a vector of linked fonts corresponding to |font|.
   const std::vector<Font>* GetLinkedFonts(const Font& font) const;
 
   // 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 GetRunContainingCaret(const SelectionModel& caret) 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.
@@ skipping 21 matching lines @@
   scoped_array<int> logical_to_visual_;
 
   bool needs_layout_;
 
   DISALLOW_COPY_AND_ASSIGN(RenderTextWin);
 };
 
 }  // namespace gfx
 
 #endif  // UI_GFX_RENDER_TEXT_WIN_H_