Add logic to switch to DirectWrite font proxy via field trial.

chrome/utility/font_cache_handler_win.h

 // 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.
 
 #ifndef CHROME_UTILITY_FONT_CACHE_HANDLER_WIN_H_
 #define CHROME_UTILITY_FONT_CACHE_HANDLER_WIN_H_
 
 #include "base/files/file_path.h"
-#include "base/macros.h"
 #include "base/memory/ref_counted.h"
 #include "base/memory/scoped_ptr.h"
 #include "chrome/utility/utility_message_handler.h"
 
 namespace base {
 class TaskRunner;
 class Thread;
 }
 
 // Handles requests to build a static direct write font cache. Must be invoked
@@ skipping 18 matching lines @@
   scoped_refptr<base::TaskRunner> utility_task_runner_;
 
   // Thread that caching process runs on, while FontCacheHandler handles
   // messages from the browser process.
   scoped_ptr<base::Thread> cache_thread_;
 
   DISALLOW_COPY_AND_ASSIGN(FontCacheHandler);
 };
 
 #endif  // CHROME_UTILITY_FONT_CACHE_HANDLER_WIN_H_