[2/4]Allow hotplugging of primary DRM device

ui/ozone/platform/drm/gbm_surface_factory.cc

 // 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.
 
 #include "ui/ozone/platform/drm/gbm_surface_factory.h"
 
 #include <gbm.h>
 
 #include "base/command_line.h"
 #include "base/files/file_path.h"
@@ skipping 65 matching lines @@
 GbmSurfaceFactory::~GbmSurfaceFactory() {
 }
 
 void GbmSurfaceFactory::InitializeGpu(DrmDeviceManager* drm_device_manager,
                                       ScreenManager* screen_manager) {
   drm_device_manager_ = drm_device_manager;
   screen_manager_ = screen_manager;
 }
 
 intptr_t GbmSurfaceFactory::GetNativeDisplay() {
-#if defined(USE_MESA_PLATFORM_NULL)
   return EGL_DEFAULT_DISPLAY;
-#else
-  scoped_refptr<GbmDevice> gbm = GetGbmDevice(gfx::kNullAcceleratedWidget);
-  DCHECK(gbm);
-  return reinterpret_cast<intptr_t>(gbm->device());
-#endif
 }
 
 const int32* GbmSurfaceFactory::GetEGLSurfaceProperties(
     const int32* desired_list) {
   static const int32 kConfigAttribs[] = {EGL_BUFFER_SIZE,
                                          32,
                                          EGL_ALPHA_SIZE,
                                          8,
                                          EGL_BLUE_SIZE,
                                          8,
@@ skipping 114 matching lines @@
   return false;
 }
 
 scoped_refptr<GbmDevice> GbmSurfaceFactory::GetGbmDevice(
     gfx::AcceleratedWidget widget) {
   return static_cast<GbmDevice*>(
       drm_device_manager_->GetDrmDevice(widget).get());
 }
 
 }  // namespace ui