[Ozone-Dri] Decouple the IO helper thread from DriWrapper

ui/ozone/platform/dri/ozone_platform_gbm.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/dri/ozone_platform_gbm.h"
 
 #include <dlfcn.h>
 #include <gbm.h>
 #include <stdlib.h>
 
@@ skipping 134 matching lines @@
         make_scoped_ptr(new StubKeyboardLayoutEngine()));
 #endif
     event_factory_ozone_.reset(new EventFactoryEvdev(
         cursor_.get(), device_manager_.get(),
         KeyboardLayoutEngineManager::GetKeyboardLayoutEngine()));
   }
 
   void InitializeGPU() override {
     gl_api_loader_.reset(new GlApiLoader());
     // Async page flips are supported only on surfaceless mode.
-    gbm_.reset(new GbmWrapper(kDefaultGraphicsCardPath, !use_surfaceless_));
+    gbm_.reset(new GbmWrapper(kDefaultGraphicsCardPath));
     gbm_->Initialize();
     buffer_generator_.reset(new GbmBufferGenerator());
     screen_manager_.reset(
         new ScreenManager(gbm_.get(), buffer_generator_.get()));
     window_delegate_manager_.reset(new DriWindowDelegateManager());
     if (!surface_factory_ozone_)
       surface_factory_ozone_.reset(new GbmSurfaceFactory(use_surfaceless_));
 
     surface_factory_ozone_->InitializeGpu(gbm_.get(), screen_manager_.get(),
                                           window_delegate_manager_.get());
@@ skipping 38 matching lines @@
 OzonePlatform* CreateOzonePlatformGbm() {
   base::CommandLine* cmd = base::CommandLine::ForCurrentProcess();
 #if defined(USE_MESA_PLATFORM_NULL)
   // Only works with surfaceless.
   cmd->AppendSwitch(switches::kOzoneUseSurfaceless);
 #endif
   return new OzonePlatformGbm(cmd->HasSwitch(switches::kOzoneUseSurfaceless));
 }
 
 }  // namespace ui