Revert "Use TaskScheduler instead of WorkerPool in x11_hotplug_event_handler.cc."

ui/compositor/test/test_suite.cc

 // Copyright (c) 2012 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/compositor/test/test_suite.h"
 
 #include "base/command_line.h"
-#include "base/memory/ptr_util.h"
-#include "base/test/scoped_task_environment.h"
+#include "base/message_loop/message_loop.h"
 #include "build/build_config.h"
 #include "ui/compositor/compositor.h"
 #include "ui/compositor/compositor_switches.h"
 #include "ui/compositor/layer.h"
 #include "ui/gfx/gfx_paths.h"
 #include "ui/gl/test/gl_surface_test_support.h"
 
 #if defined(USE_OZONE)
 #include "ui/ozone/public/ozone_platform.h"
 #endif
@@ skipping 17 matching lines @@
 #if defined(USE_OZONE)
   ui::OzonePlatform::InitializeForUI();
 #endif
 
   gfx::RegisterPathProvider();
 
 #if defined(OS_WIN)
   display::win::SetDefaultDeviceScaleFactor(1.0f);
 #endif
 
-  scoped_task_environment_ =
-      base::MakeUnique<base::test::ScopedTaskEnvironment>(
-          base::test::ScopedTaskEnvironment::MainThreadType::UI);
+  message_loop_.reset(new base::MessageLoopForUI);
 }
 
 void CompositorTestSuite::Shutdown() {
-  scoped_task_environment_.reset();
+  message_loop_.reset();
 
   base::TestSuite::Shutdown();
 }
 
 }  // namespace test
 }  // namespace ui