[Ozone-DRI] Re-enable GBM surface mode support

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 128 matching lines @@
 #else
     KeyboardLayoutEngineManager::SetKeyboardLayoutEngine(
         make_scoped_ptr(new StubKeyboardLayoutEngine()));
 #endif
     event_factory_ozone_.reset(new EventFactoryEvdev(
         window_manager_->cursor(), device_manager_.get(),
         KeyboardLayoutEngineManager::GetKeyboardLayoutEngine()));
   }
 
   void InitializeGPU() override {
-    dri_.reset(new DriWrapper(kDefaultGraphicsCardPath, false));
+    // Async page flips are supported only on surfaceless mode.
+    dri_.reset(new DriWrapper(kDefaultGraphicsCardPath, !use_surfaceless_));
     dri_->Initialize();
     buffer_generator_.reset(new GbmBufferGenerator(dri_.get()));
     screen_manager_.reset(
         new ScreenManager(dri_.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(
         dri_.get(), buffer_generator_->device(), screen_manager_.get(),
@@ skipping 33 matching lines @@
 };
 
 }  // namespace
 
 OzonePlatform* CreateOzonePlatformGbm() {
   base::CommandLine* cmd = base::CommandLine::ForCurrentProcess();
   return new OzonePlatformGbm(cmd->HasSwitch(switches::kOzoneUseSurfaceless));
 }
 
 }  // namespace ui