fix know issues in RenderText

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>
 
@@ skipping 45 matching lines @@
   // Overridden from RenderText:
   virtual void SetText(const string16& text) OVERRIDE;
   virtual void SetDisplayRect(const Rect& r) OVERRIDE;
   virtual void ApplyStyleRange(StyleRange style_range) OVERRIDE;
   virtual void ApplyDefaultStyle() OVERRIDE;
   virtual int GetStringWidth() OVERRIDE;
   virtual void Draw(Canvas* canvas) OVERRIDE;
   virtual SelectionModel FindCursorPosition(const Point& point) OVERRIDE;
   virtual Rect GetCursorBounds(const SelectionModel& selection,
                                bool insert_mode) OVERRIDE;
+  virtual size_t GetIndexOfNextGrapheme(size_t position) OVERRIDE;
 
  protected:
   // Overridden from RenderText:
   virtual SelectionModel GetLeftSelectionModel(const SelectionModel& current,
                                                BreakType break_type) OVERRIDE;
   virtual SelectionModel GetRightSelectionModel(const SelectionModel& current,
                                                 BreakType break_type) OVERRIDE;
   virtual SelectionModel LeftEndSelectionModel() OVERRIDE;
   virtual SelectionModel RightEndSelectionModel() OVERRIDE;
   virtual size_t GetIndexOfPreviousGrapheme(size_t position) OVERRIDE;
   virtual std::vector<Rect> GetSubstringBounds(size_t from, size_t to) OVERRIDE;
+  virtual bool IsCursorablePosition(size_t position) OVERRIDE;
 
  private:
   void ItemizeLogicalText();
   void LayoutVisualText(HDC hdc);
 
   // 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;
 
@@ skipping 33 matching lines @@
 
   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_