Mac: Implement GetFallbackFontFamilies for Harfbuzz

ui/gfx/render_text_unittest.cc

 // 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.
 
 #include "ui/gfx/render_text.h"
 
 #include <algorithm>
 
 #include "base/format_macros.h"
 #include "base/i18n/break_iterator.h"
@@ skipping 2551 matching lines @@
   render_text.SetFontList(font_list);
   // Korean character "han".
   render_text.SetText(WideToUTF16(L"\xd55c"));
   render_text.EnsureLayout();
   internal::TextRunList* run_list = render_text.GetRunList();
   ASSERT_EQ(1U, run_list->size());
   EXPECT_EQ(0U, run_list->runs()[0]->CountMissingGlyphs());
 }
 #endif  // defined(OS_WIN)
 
+// Ensure that the fallback fonts offered by gfx::GetFallbackFontFamilies() are
+// tried. Note this test assumes the font "Arial" doesn't provide a unicode
+// glyph for a particular character, and that there exists a system fallback
+// font which does.
+#if defined(OS_WIN) || defined(OS_MACOSX)
+TEST_F(RenderTextTest, HarfBuzz_UnicodeFallback) {
+  RenderTextHarfBuzz render_text;
+  render_text.SetFontList(FontList("Arial, 12px"));
+
+  // Korean character "han".
+  render_text.SetText(WideToUTF16(L"\xd55c"));
+  render_text.EnsureLayout();
+  internal::TextRunList* run_list = render_text.GetRunList();
+  ASSERT_EQ(1U, run_list->size());
+  EXPECT_EQ(0U, run_list->runs()[0]->CountMissingGlyphs());
+}
+#endif  // defined(OS_WIN) || defined(OS_MACOSX)
+
 // Ensure that the width reported by RenderText is sufficient for drawing. Draws
 // to a canvas and checks whether any pixel beyond the width is colored.
 TEST_F(RenderTextTest, TextDoesntClip) {
   const wchar_t* kTestStrings[] = { L"Save", L"Remove", L"TEST", L"W", L"WWW" };
   const Size kCanvasSize(300, 50);
   const int kTestWidth = 10;
 
   skia::RefPtr<SkSurface> surface = skia::AdoptRef(
       SkSurface::NewRasterN32Premul(kCanvasSize.width(), kCanvasSize.height()));
   scoped_ptr<Canvas> canvas(
@@ skipping 20 matching lines @@
       EXPECT_LT(220U, color_utils::GetLuminanceForColor(color)) << string;
       for (int x = 1; x < kTestWidth; ++x) {
         color = buffer[width + x + y * kCanvasSize.width()];
         EXPECT_EQ(SK_ColorWHITE, color) << string;
       }
     }
   }
 }
 
 }  // namespace gfx