Allow the default generic font family settings to find the first available font

ui/gfx/font.h

 // 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.
 
 #ifndef UI_GFX_FONT_H_
 #define UI_GFX_FONT_H_
 
 #include <string>
 
 #include "base/memory/ref_counted.h"
@@ skipping 112 matching lines @@
   // Windows: This handle is owned by the Font object, and should not be
   //          destroyed by the caller.
   // Mac:     The object is owned by the system and should not be released.
   NativeFont GetNativeFont() const;
 #endif
 
   // Raw access to the underlying platform font implementation. Can be
   // static_cast to a known implementation type if needed.
   PlatformFont* platform_font() const { return platform_font_.get(); }
 
+  // Returns the first available font name. If there is no available font,
+  // returns the first font name. Empty entries are ignored.
+  // Used by Blink and webui to pick the primary standard/serif/sans/fixed/etc.
+  // fonts from region-specific IDS lists.
+  static std::string FirstAvailableOrFirst(const std::string& font_name_list);

[msw, 2016/10/28 07:05:06]

This probably shouldn't be a Font class member function; I'd add it to new
font_util.h|cc files, maybe to skia_util.h|cc, or perhaps as a static FontList
member (it's somewhat related, but not even used there...) but I've given you
bad advice before, so feel free to ask another gfx owner :)

[kojii, 2016/10/28 07:57:30]

FontList makes perfect sense to me, I was actually wondering which is better.
Thank you for this many round of reviews, please don't call the efforts to seek
for better as bad ;)

+
  private:
   // Wrapped platform font implementation.
   scoped_refptr<PlatformFont> platform_font_;
 };
 
 #ifndef NDEBUG
 GFX_EXPORT std::ostream& operator<<(std::ostream& stream,
                                     const Font::Weight weight);
 #endif
 
 }  // namespace gfx
 
 #endif  // UI_GFX_FONT_H_