MacViews: Use RenderTextHarfBuzz only for Textfields

ui/gfx/render_text_harfbuzz.h

 // Copyright 2014 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_HARFBUZZ_H_
 #define UI_GFX_RENDER_TEXT_HARFBUZZ_H_
 
 #include "base/memory/scoped_ptr.h"
 #include "base/memory/scoped_vector.h"
 #include "third_party/harfbuzz-ng/src/hb.h"
@@ skipping 69 matching lines @@
 };
 
 }  // namespace internal
 
 class GFX_EXPORT RenderTextHarfBuzz : public RenderText {
  public:
   RenderTextHarfBuzz();
   ~RenderTextHarfBuzz() override;
 
   // Overridden from RenderText.
+  scoped_ptr<RenderText> CreateInstanceOfSameType() const override;
   Size GetStringSize() override;
   SizeF GetStringSizeF() override;
   SelectionModel FindCursorPosition(const Point& point) override;
   std::vector<FontSpan> GetFontSpansForTesting() override;
   Range GetGlyphBounds(size_t index) override;
 
  protected:
   // Overridden from RenderText.
   int GetLayoutTextBaseline() override;
   SelectionModel AdjacentCharSelectionModel(
@@ skipping 65 matching lines @@
   // ICU grapheme iterator for the layout text. Valid when |!needs_layout_|. Can
   // be NULL in case of an error.
   scoped_ptr<base::i18n::BreakIterator> grapheme_iterator_;
 
   DISALLOW_COPY_AND_ASSIGN(RenderTextHarfBuzz);
 };
 
 }  // namespace gfx
 
 #endif  // UI_GFX_RENDER_TEXT_HARFBUZZ_H_