Merging to M42

ui/gfx/render_text_harfbuzz.cc

 // 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.
 
 #include "ui/gfx/render_text_harfbuzz.h"
 
 #include <limits>
 
 #include "base/i18n/bidi_line_iterator.h"
 #include "base/i18n/break_iterator.h"
@@ skipping 1237 matching lines @@
       GetFallbackFontFamilies(primary_family);
 
 #if defined(OS_WIN)
   // Append fonts in the fallback list of the Uniscribe font.
   if (!uniscribe_family.empty()) {
     std::vector<std::string> uniscribe_fallbacks =
         GetFallbackFontFamilies(uniscribe_family);
     fallback_families.insert(fallback_families.end(),
         uniscribe_fallbacks.begin(), uniscribe_fallbacks.end());
   }
+
+  // Add Segoe UI and its associated linked fonts to the fallback font list to
+  // ensure that the fallback list covers the basic cases.
+  // http://crbug.com/467459. On some Windows configurations the default font
+  // could be a raster font like System, which would not give us a reasonable
+  // fallback font list.
+  std::vector<std::string> default_fallback_families =
+      GetFallbackFontFamilies("Segoe UI");
+  fallback_families.insert(fallback_families.end(),
+      default_fallback_families.begin(), default_fallback_families.end());
 #endif
 
   // Try shaping with the fallback fonts.
   for (const auto& family : fallback_families) {
     if (family == primary_family)
       continue;
 #if defined(OS_WIN)
     if (family == uniscribe_family)
       continue;
 #endif
@@ skipping 200 matching lines @@
   DCHECK(!update_layout_run_list_);
   DCHECK(!update_display_run_list_);
   return text_elided() ? display_run_list_.get() : &layout_run_list_;
 }
 
 const internal::TextRunList* RenderTextHarfBuzz::GetRunList() const {
   return const_cast<RenderTextHarfBuzz*>(this)->GetRunList();
 }
 
 }  // namespace gfx