Implement font fallback in RenderTextWin.

ui/gfx/render_text_win.h

Index: ui/gfx/render_text_win.h
===================================================================
--- ui/gfx/render_text_win.h	(revision 109873)
+++ ui/gfx/render_text_win.h	(working copy)
@@ -43,6 +43,7 @@
   scoped_array<int> advance_widths;
   scoped_array<GOFFSET> offsets;
   ABC abc_widths;
+  SCRIPT_CACHE script_cache;
 
  private:
   DISALLOW_COPY_AND_ASSIGN(TextRun);
@@ -89,8 +90,8 @@
   // 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.
@@ -111,8 +112,6 @@
   SCRIPT_CONTROL script_control_;
   SCRIPT_STATE script_state_;
 
-  SCRIPT_CACHE script_cache_;
-
   std::vector<internal::TextRun*> runs_;
   int string_width_;