RenderTextHarfBuzz: Implement font fallback for Win and Linux

ui/gfx/font_fallback_win_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/font_fallback_win.h"
 #include "testing/gtest/include/gtest/gtest.h"
 
 namespace gfx {
 
 namespace {
 
 // Subclass of LinkedFontsIterator for testing that allows mocking the linked
 // fonts vector.
-class TestLinkedFontsIterator : public LinkedFontsIterator {
+class TestLinkedFontsIterator : public internal::LinkedFontsIterator {
  public:
   explicit TestLinkedFontsIterator(Font font) : LinkedFontsIterator(font) {
   }
 
   virtual ~TestLinkedFontsIterator() {
   }
 
   // Add a linked font to the mocked vector of linked fonts.
   void AddLinkedFontForTesting(Font font) {
     test_linked_fonts.push_back(font);
@@ skipping 83 matching lines @@
   EXPECT_TRUE(iterator.NextFont(&font));
   ASSERT_EQ("Tahoma", font.GetFontName());
 
   EXPECT_TRUE(iterator.NextFont(&font));
   ASSERT_EQ("Times New Roman", font.GetFontName());
 
   EXPECT_FALSE(iterator.NextFont(&font));
 }
 
 }  // namespace gfx