Add two pixel-based compositor unittests.

ui/gfx/compositor/test_suite.h

-// Copyright (c) 2011 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_GFX_COMPOSITOR_TEST_SUITE_H_
-#define UI_GFX_COMPOSITOR_TEST_SUITE_H_
-#pragma once
-
-#include "base/compiler_specific.h"
-#include "base/memory/scoped_ptr.h"
-#include "base/test/test_suite.h"
-
-namespace ui {
-class WebKitPlatformSupportImpl;
-}  // namespace ui
-
-class MessageLoop;
-
-class CompositorTestSuite : public base::TestSuite {
- public:
-  CompositorTestSuite(int argc, char** argv);
-  ~CompositorTestSuite();
-
- protected:
-  // base::TestSuite:
-  virtual void Initialize() OVERRIDE;
-  virtual void Shutdown() OVERRIDE;
-
- private:
-  scoped_ptr<MessageLoop> message_loop_;
-};
-
-#endif  // UI_GFX_COMPOSITOR_TEST_SUITE_H_