Remove unnecessary ui::CompositorTestSupport

ui/compositor/test/compositor_test_support.h

-// 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.
-
-#ifndef UI_COMPOSITOR_TEST_COMPOSITOR_TEST_SUPPORT_H_
-#define UI_COMPOSITOR_TEST_COMPOSITOR_TEST_SUPPORT_H_
-
-namespace ui {
-
-class CompositorTestSupport {
- public:
-  // Called by programs that want to use a real compositor,
-  // but skip the typical initialization of browser_main.cc.
-  static void Initialize();
-  static void Terminate();
-};
-
-}  // namespace ui
-
-#endif  // UI_COMPOSITOR_TEST_COMPOSITOR_TEST_SUPPORT_H_