Use GpuPreferences to avoid directly accessing switches in gpu related code

content/gpu/gpu_main.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 <stddef.h>
 #include <stdlib.h>
 
 #include <utility>
 
 #include "base/lazy_instance.h"
@@ skipping 383 matching lines @@
 
   gpu::SyncPointManager sync_point_manager(false);
 
   base::ThreadPriority io_thread_priority = base::ThreadPriority::NORMAL;
 #if defined(OS_ANDROID) || defined(OS_CHROMEOS)
   io_thread_priority = base::ThreadPriority::DISPLAY;
 #endif
 
   GpuProcess gpu_process(io_thread_priority);
 
+  const gpu::GpuPreferences* kGpuPreferences = nullptr;

[boliu, 2016/02/26 22:17:32]

style: kGpuPreferences is only for static/global constants I think

[Peng, 2016/02/29 16:09:22]

Done.

   GpuChildThread* child_thread = new GpuChildThread(
+      kGpuPreferences,
       watchdog_thread.get(), dead_on_arrival, gpu_info, deferred_messages.Get(),
       gpu_memory_buffer_factory.get(),
       &sync_point_manager);
   while (!deferred_messages.Get().empty())
     deferred_messages.Get().pop();
 
   child_thread->Init(start_time);
 
   gpu_process.set_main_thread(child_thread);
 
@@ skipping 178 matching lines @@
     return true;
   }
 
   return false;
 }
 #endif  // defined(OS_WIN)
 
 }  // namespace.
 
 }  // namespace content