Use GpuPreferences to avoid directly accessing switches in gpu related code

content/gpu/in_process_gpu_thread.h

 // Copyright 2013 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 CONTENT_GPU_IN_PROCESS_GPU_THREAD_H_
 #define CONTENT_GPU_IN_PROCESS_GPU_THREAD_H_
 
 #include "base/macros.h"
 #include "base/threading/thread.h"
 #include "content/common/content_export.h"
 #include "content/common/in_process_child_thread_params.h"
 
 namespace gpu {
+struct GpuPreferences;
 class SyncPointManager;
 }
 
 namespace content {
 
 class GpuMemoryBufferFactory;
 class GpuProcess;
 
 // This class creates a GPU thread (instead of a GPU process), when running
 // with --in-process-gpu or --single-process.
 class InProcessGpuThread : public base::Thread {
  public:
   InProcessGpuThread(const InProcessChildThreadParams& params,
+                     const gpu::GpuPreferences* gpu_preferences,
                      gpu::SyncPointManager* sync_point_manager_override);
   ~InProcessGpuThread() override;
 
  protected:
   void Init() override;
   void CleanUp() override;
 
  private:
   InProcessChildThreadParams params_;
 
   // Deleted in CleanUp() on the gpu thread, so don't use smart pointers.
   GpuProcess* gpu_process_;
 
+  const gpu::GpuPreferences* const gpu_preferences_;
+
   // Can be null if overridden.
   scoped_ptr<gpu::SyncPointManager> sync_point_manager_;
 
   // Non-owning.
   gpu::SyncPointManager* sync_point_manager_override_;
 
   scoped_ptr<GpuMemoryBufferFactory> gpu_memory_buffer_factory_;
 
   DISALLOW_COPY_AND_ASSIGN(InProcessGpuThread);
 };
 
 CONTENT_EXPORT base::Thread* CreateInProcessGpuThread(
     const InProcessChildThreadParams& params);
 
 }  // namespace content
 
 #endif  // CONTENT_GPU_IN_PROCESS_GPU_THREAD_H_