[rendertext,i18n] Added flag to force RTL rendering

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 <stddef.h>
 #include <stdint.h>
 
@@ skipping 191 matching lines @@
   size_t GetRunContainingCaret(const SelectionModel& caret);
 
   // 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(
       const internal::TextRunHarfBuzz* run);
   SelectionModel LastSelectionModelInsideRun(
       const internal::TextRunHarfBuzz* run);
 
+  void CheckForcedDirection(UBiDiLevel* level);
+
   // Break the text into logical runs and populate the visual <-> logical maps
   // into |run_list_out|.
   void ItemizeTextToRuns(const base::string16& string,
                          internal::TextRunList* run_list_out);
 
   // Helper method for ShapeRun() that calls ShapeRunWithFont() with |text|,
   // |run|, |font|, and |render_params|, returning true if the font provides
   // all the glyphs needed for |run|, and false otherwise. Additionally updates
   // |best_font|, |best_render_params|, and |best_missing_glyphs| if |font|
   // has fewer than |best_missing_glyphs| missing glyphs.
@@ skipping 48 matching lines @@
 
   // Fixed width of glyphs. This should only be set in test environments.
   float glyph_width_for_test_;
 
   DISALLOW_COPY_AND_ASSIGN(RenderTextHarfBuzz);
 };
 
 }  // namespace gfx
 
 #endif  // UI_GFX_RENDER_TEXT_HARFBUZZ_H_