Make MediaSession available on Desktop

content/browser/media/android/browser_media_session_manager.h

-// Copyright 2015 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_MEDIA_ANDROID_BROWSER_MEDIA_SESSION_MANAGER_H_
-#define CONTENT_BROWSER_MEDIA_ANDROID_BROWSER_MEDIA_SESSION_MANAGER_H_
-
-#include "base/macros.h"
-#include "base/optional.h"
-#include "content/common/content_export.h"
-
-namespace IPC {
-class Message;
-}  // namespace IPC
-
-namespace content {
-
-class RenderFrameHost;
-struct MediaMetadata;
-
-class CONTENT_EXPORT BrowserMediaSessionManager {
- public:
-  explicit BrowserMediaSessionManager(RenderFrameHost* render_frame_host);
-
-  virtual void OnSetMetadata(int session_id,
-                             const base::Optional<MediaMetadata>& metadata);
-
- private:
-  RenderFrameHost* const render_frame_host_;
-
-  DISALLOW_COPY_AND_ASSIGN(BrowserMediaSessionManager);
-};
-
-}  // namespace content
-
-#endif  // CONTENT_BROWSER_MEDIA_ANDROID_BROWSER_MEDIA_SESSION_MANAGER_H_