Add more out of line copy ctors for complex classes.

gpu/command_buffer/service/gpu_preferences.h

 // Copyright 2016 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 GPU_COMMAND_BUFFER_SERVICE_GPU_PREFERENCES_H_
 #define GPU_COMMAND_BUFFER_SERVICE_GPU_PREFERENCES_H_
 
 #include <stddef.h>
 
 #include "base/macros.h"
 #include "build/build_config.h"
 #include "gpu/command_buffer/common/constants.h"
 #include "gpu/gpu_export.h"
 
 namespace gpu {
 
 struct GPU_EXPORT GpuPreferences {
  public:
   GpuPreferences();
 
+  GpuPreferences(const GpuPreferences& other);
+
   ~GpuPreferences();
 
   // ===================================
   // Settings from //content/public/common/content_switches.h
 
   // Runs the renderer and plugins in the same process as the browser.
   bool single_process = false;
 
   // Run the GPU process as a thread in the browser process.
   bool in_process_gpu = false;
@@ skipping 88 matching lines @@
   // Turns on calling TRACE for every GL call.
   bool enable_gpu_service_tracing = false;
 
   // Enable OpenGL ES 3 APIs without proper service side validation.
   bool enable_unsafe_es3_apis = false;
 };
 
 }  // namespace gpu
 
 #endif // GPU_COMMAND_BUFFER_SERVICE_GPU_PREFERENCES_H_