ozone: Add atomic initialization path

ui/ozone/platform/drm/gpu/gbm_device.h

 // Copyright 2015 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_OZONE_PLATFORM_DRM_GPU_GBM_DEVICE_H_
 #define UI_OZONE_PLATFORM_DRM_GPU_GBM_DEVICE_H_
 
 #include "ui/ozone/platform/drm/gpu/drm_device.h"
 
 struct gbm_device;
 
 namespace ui {
 
 class GbmDevice : public DrmDevice {
  public:
   GbmDevice(const base::FilePath& device_path);
   GbmDevice(const base::FilePath& device_path, base::File file);
 
   gbm_device* device() const { return device_; }
 
   // DrmDevice implementation:
-  bool Initialize() override;
+  bool Initialize(bool use_atomic) override;
 
  private:
   ~GbmDevice() override;
 
   gbm_device* device_;
 
   DISALLOW_COPY_AND_ASSIGN(GbmDevice);
 };
 
 }  // namespace ui
 
 #endif  // UI_OZONE_PLATFORM_DRM_GPU_GBM_DEVICE_H_