Remove unused MockMediaObserver

content/browser/renderer_host/media/mock_media_observer.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 CONTENT_BROWSER_RENDERER_HOST_MEDIA_MOCK_MEDIA_OBSERVER_H_
-#define CONTENT_BROWSER_RENDERER_HOST_MEDIA_MOCK_MEDIA_OBSERVER_H_
-
-#include <string>
-
-#include "base/basictypes.h"
-#include "content/public/browser/media_observer.h"
-#include "media/audio/audio_parameters.h"
-#include "media/base/media_log_event.h"
-#include "testing/gmock/include/gmock/gmock.h"
-
-namespace content {
-
-class MockMediaObserver : public MediaObserver {
- public:
-  MockMediaObserver();
-  virtual ~MockMediaObserver();
-
-  MOCK_METHOD6(OnMediaRequestStateChanged,
-               void(int render_process_id, int render_frame_id,
-                    int page_request_id, const GURL& security_origin,
-                    MediaStreamType stream_type,
-                    const MediaRequestState state));
-};
-
-}  // namespace content
-
-#endif  // CONTENT_BROWSER_RENDERER_HOST_MEDIA_MOCK_MEDIA_OBSERVER_H_