Fix a crash in MediaSessionServiceImpl due to life time issue

content/browser/media/session/media_session_impl.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_SESSION_MEDIA_SESSION_IMPL_H_
 #define CONTENT_BROWSER_MEDIA_SESSION_MEDIA_SESSION_IMPL_H_
 
 #include <stddef.h>
 
 #include <map>
@@ skipping 148 matching lines @@
   // session requests audio focus.
   CONTENT_EXPORT AudioFocusManager::AudioFocusType audio_focus_type() const {
     return audio_focus_type_;
   }
 
   // Returns whether the session has Pepper instances.
   bool HasPepper() const;
 
   // WebContentsObserver implementation
   void WebContentsDestroyed() override;
+  void RenderFrameDeleted(RenderFrameHost* rfh) override;
 
   // MediaSessionService-related methods
 
   // Called when a MediaSessionService is created, which registers itself to
   // this session.
   void OnServiceCreated(MediaSessionServiceImpl* service);
   // Called when a MediaSessionService is destroyed, which unregisters itself
   // from this session.
   void OnServiceDestroyed(MediaSessionServiceImpl* service);
 
@@ skipping 132 matching lines @@
   ServicesMap services_;
   // The currently routed service (non-owned pointer).
   MediaSessionServiceImpl* routed_service_;
 
   DISALLOW_COPY_AND_ASSIGN(MediaSessionImpl);
 };
 
 }  // namespace content
 
 #endif  // CONTENT_BROWSER_MEDIA_SESSION_MEDIA_SESSION_IMPL_H_