Makes RenderFrameObserver/RenderViewObserver::OnDestruct pure virtual.

content/renderer/media/android/renderer_media_player_manager.h

 // Copyright 2013 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_RENDERER_MEDIA_ANDROID_RENDERER_MEDIA_PLAYER_MANAGER_H_
 #define CONTENT_RENDERER_MEDIA_ANDROID_RENDERER_MEDIA_PLAYER_MANAGER_H_
 
 #include <map>
 #include <string>
 
@@ skipping 98 matching lines @@
 
   // Gets the pointer to WebMediaPlayerAndroid given the |player_id|.
   media::RendererMediaPlayerInterface* GetMediaPlayer(int player_id);
 
 #if defined(VIDEO_HOLE)
   // Gets the list of media players with video geometry changes.
   void RetrieveGeometryChanges(std::map<int, gfx::RectF>* changes);
 #endif  // defined(VIDEO_HOLE)
 
  private:
+  // RenderFrameObserver implementation.
+  void OnDestruct() override;
+
   // Message handlers.
   void OnMediaMetadataChanged(int player_id,
                               base::TimeDelta duration,
                               int width,
                               int height,
                               bool success);
   void OnMediaPlaybackCompleted(int player_id);
   void OnMediaBufferingUpdate(int player_id, int percent);
   void OnSeekRequest(int player_id, const base::TimeDelta& time_to_seek);
   void OnSeekCompleted(int player_id,
@@ skipping 20 matching lines @@
   std::map<int, media::RendererMediaPlayerInterface*> media_players_;
 
   int next_media_player_id_;
 
   DISALLOW_COPY_AND_ASSIGN(RendererMediaPlayerManager);
 };
 
 }  // namespace content
 
 #endif  // CONTENT_RENDERER_MEDIA_ANDROID_RENDERER_MEDIA_PLAYER_MANAGER_H_