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"
 #include "base/memory/scoped_ptr.h"
 #include "base/strings/string_split.h"
 #include "base/strings/string_util.h"
 #include "base/strings/stringprintf.h"
 #include "base/strings/utf_string_conversions.h"
 #include "testing/gtest/include/gtest/gtest.h"
 #include "third_party/skia/include/core/SkSurface.h"
 #include "ui/gfx/break_list.h"
 #include "ui/gfx/canvas.h"
 #include "ui/gfx/color_utils.h"
 #include "ui/gfx/font.h"
+#include "ui/gfx/font_fallback.h"
 #include "ui/gfx/range/range.h"
 #include "ui/gfx/range/range_f.h"
 #include "ui/gfx/render_text_harfbuzz.h"
 
 #if defined(OS_WIN)
 #include "base/win/windows_version.h"
 #include "ui/gfx/platform_font_win.h"
 #endif
 
 using base::ASCIIToUTF16;
@@ skipping 2530 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)
+
+// A targeted test for GetFallbackFontFamilies on Mac. It uses a system API that
+// only became publicly available in the 10.8 SDK. This test is to ensure it
+// behaves sensibly on all supported OS versions.
+#if defined(OS_MACOSX)
+TEST_F(RenderTextTest, HarfBuzz_GetFallbackFontFamilies) {
+  std::vector<std::string> fallback_families = GetFallbackFontFamilies("Arial");

[Alexei Svitkine (slow), 2015/03/04 16:23:02]

Sounds like this should be in font_fallback_mac_unittest.cc.

[tapted, 2015/03/04 23:44:35]

Done.

+  // If there is only one fallback, it means the only fallback is the font
+  // itself.
+  EXPECT_LT(1u, fallback_families.size());
+}
+#endif  // 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