Remove WebKit::Platform dependencies from cc

cc/test/web_compositor_initializer.h

-// Copyright 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 WebCompositorInitializer_h
-#define WebCompositorInitializer_h
-
-#include "base/basictypes.h"
-#include <public/Platform.h>
-#include <public/WebCompositorSupport.h>
-
-namespace WebKit {
-class WebThread;
-}
-
-namespace WebKitTests {
-
-class WebCompositorInitializer {
-public:
-    explicit WebCompositorInitializer(WebKit::WebThread* thread)
-    {
-        WebKit::Platform::current()->compositorSupport()->initialize(thread);
-    }
-
-    ~WebCompositorInitializer()
-    {
-        WebKit::Platform::current()->compositorSupport()->shutdown();
-    }
-
-private:
-    DISALLOW_COPY_AND_ASSIGN(WebCompositorInitializer);
-};
-
-}
-
-#endif // WebCompositorInitializer_h