Mac: Implement GetFallbackFontFamilies for Harfbuzz

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 157 matching lines @@
   FRIEND_TEST_ALL_PREFIXES(RenderTextTest, HarfBuzz_RunDirection);
   FRIEND_TEST_ALL_PREFIXES(RenderTextTest, HarfBuzz_HorizontalPositions);
   FRIEND_TEST_ALL_PREFIXES(RenderTextTest,
                            HarfBuzz_TextPositionWithFractionalSize);
   FRIEND_TEST_ALL_PREFIXES(RenderTextTest, HarfBuzz_BreakRunsByUnicodeBlocks);
   FRIEND_TEST_ALL_PREFIXES(RenderTextTest, HarfBuzz_BreakRunsByEmoji);
   FRIEND_TEST_ALL_PREFIXES(RenderTextTest, HarfBuzz_SubglyphGraphemeCases);
   FRIEND_TEST_ALL_PREFIXES(RenderTextTest, HarfBuzz_SubglyphGraphemePartition);
   FRIEND_TEST_ALL_PREFIXES(RenderTextTest, HarfBuzz_NonExistentFont);
   FRIEND_TEST_ALL_PREFIXES(RenderTextTest, HarfBuzz_UniscribeFallback);
+  FRIEND_TEST_ALL_PREFIXES(RenderTextTest, HarfBuzz_UnicodeFallback);
 
   // Specify the width of a glyph for test. The width of glyphs is very
   // platform-dependent and environment-dependent. Otherwise multiline test
   // will become really flaky.
   void set_glyph_width_for_test(float test_width) {
     glyph_width_for_test_ = test_width;
   }
 
   // The actual implementation of the text drawing.
   void DrawVisualTextInternal(internal::SkiaTextRenderer* renderer);
@@ skipping 77 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_