MacViews: Use RenderTextHarfBuzz only for Textfields

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 45 matching lines @@
 
 }  // namespace internal
 
 // RenderTextWin is the Windows implementation of RenderText using Uniscribe.
 class RenderTextWin : public RenderText {
  public:
   RenderTextWin();
   virtual ~RenderTextWin();
 
   // Overridden from RenderText:
+  virtual scoped_ptr<RenderText> NewInstance() const override;
   virtual Size GetStringSize() override;
   virtual SelectionModel FindCursorPosition(const Point& point) override;
   virtual std::vector<FontSpan> GetFontSpansForTesting() override;
 
  protected:
   // Overridden from RenderText:
   virtual int GetLayoutTextBaseline() override;
   virtual SelectionModel AdjacentCharSelectionModel(
       const SelectionModel& selection,
       VisualCursorDirection direction) override;
@@ skipping 61 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_