Revert of ozone: Remove the "drm" software composited platform

ui/ozone/platform/drm/gpu/gbm_surface_factory.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 UI_OZONE_PLATFORM_DRM_GPU_GBM_SURFACE_FACTORY_H_
 #define UI_OZONE_PLATFORM_DRM_GPU_GBM_SURFACE_FACTORY_H_
 
-#include "base/threading/thread_checker.h"
-#include "ui/ozone/public/surface_factory_ozone.h"
+#include "ui/ozone/platform/drm/gpu/drm_surface_factory.h"
 
 namespace ui {
 
 class DrmDeviceManager;
 class DrmWindow;
 class GbmDevice;
 class ScreenManager;
 
-class GbmSurfaceFactory : public SurfaceFactoryOzone {
+class GbmSurfaceFactory : public DrmSurfaceFactory {
  public:
   GbmSurfaceFactory(bool allow_surfaceless);
   ~GbmSurfaceFactory() override;
 
   void InitializeGpu(DrmDeviceManager* drm_device_manager,
                      ScreenManager* screen_manager);
 
   // DrmSurfaceFactory:
   intptr_t GetNativeDisplay() override;
   const int32_t* GetEGLSurfaceProperties(const int32_t* desired_list) override;
@@ skipping 12 matching lines @@
       gfx::BufferFormat format,
       gfx::BufferUsage usage) override;
   bool CanShowPrimaryPlaneAsOverlay() override;
 
  private:
   scoped_refptr<GbmDevice> GetGbmDevice(gfx::AcceleratedWidget widget);
 
   bool allow_surfaceless_;
 
   DrmDeviceManager* drm_device_manager_;  // Not owned.
-  ScreenManager* screen_manager_;         // Not owned.
-
-  base::ThreadChecker thread_checker_;
 
   DISALLOW_COPY_AND_ASSIGN(GbmSurfaceFactory);
 };
 
 }  // namespace ui
 
 #endif  // UI_OZONE_PLATFORM_DRM_GPU_GBM_SURFACE_FACTORY_H_