Revert changes to GPU test MessageLoop type.

gpu/test_message_loop_type.h

-// Copyright 2017 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 GPU_TEST_MESSAGE_LOOP_TYPE_H_
-#define GPU_TEST_MESSAGE_LOOP_TYPE_H_
-
-#include "base/message_loop/message_loop.h"
-
-#if defined(USE_OZONE)
-#include "ui/ozone/public/ozone_platform.h"
-#endif
-
-namespace gpu {
-namespace test {
-
-// Returns the MessageLoop type needed for GPU tests. The Ozone platform may not
-// work with TYPE_DEFAULT and this needs to be checked at runtime.
-inline base::MessageLoop::Type GetMessageLoopTypeForGpu() {
-#if defined(USE_OZONE)
-  return ui::OzonePlatform::EnsureInstance()->GetMessageLoopTypeForGpu();
-#else
-  return base::MessageLoop::TYPE_DEFAULT;
-#endif
-}
-
-}  // namespace test
-}  // namespace gpu
-
-#endif  // GPU_TEST_MESSAGE_LOOP_TYPE_H_