Makes AudioOutputProxy -> AudioOutputDispatcher reference weak.

media/audio/audio_output_dispatcher_impl.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.
 
 // AudioOutputDispatcherImpl is an implementation of AudioOutputDispatcher.
 //
 // To avoid opening and closing audio devices more frequently than necessary,
 // each dispatcher has a pool of inactive physical streams. A stream is closed
 // only if it hasn't been used for a certain period of time (specified via the
 // constructor).
@@ skipping 24 matching lines @@
 class MEDIA_EXPORT AudioOutputDispatcherImpl : public AudioOutputDispatcher {
  public:
   // |close_delay| specifies delay after the stream is idle until the audio
   // device is closed.
   AudioOutputDispatcherImpl(AudioManager* audio_manager,
                             const AudioParameters& params,
                             const std::string& output_device_id,
                             const base::TimeDelta& close_delay);
   ~AudioOutputDispatcherImpl() override;
 
-  // Opens a new physical stream if there are no pending streams in
-  // |idle_streams_|.  Do not call Close() or Stop() if this method fails.
+  // AudioOutputDispatcher implementation.
+  AudioOutputProxy* CreateStreamProxy() override;
   bool OpenStream() override;
-
-  // If there are pending streams in |idle_streams_| then it reuses one of
-  // them, otherwise creates a new one.
   bool StartStream(AudioOutputStream::AudioSourceCallback* callback,
                    AudioOutputProxy* stream_proxy) override;
-
-  // Stops the stream assigned to the specified proxy and moves it into
-  // |idle_streams_| for reuse by other proxies.
   void StopStream(AudioOutputProxy* stream_proxy) override;
-
   void StreamVolumeSet(AudioOutputProxy* stream_proxy, double volume) override;
-
-  // Closes |idle_streams_| until the number of |idle_streams_| is equal to the
-  // |idle_proxies_| count.  If there are no |idle_proxies_| a single stream is
-  // kept alive until |close_timer_| fires.
   void CloseStream(AudioOutputProxy* stream_proxy) override;
 
   // Returns true if there are any open AudioOutputProxy objects.
   bool HasOutputProxies() const;
 
   // Closes all |idle_streams_|.
   void CloseAllIdleStreams();
 
  private:
   // Creates a new physical output stream, opens it and pushes to
   // |idle_streams_|.  Returns false if the stream couldn't be created or
   // opened.
   bool CreateAndOpenStream();
 
   // Similar to CloseAllIdleStreams(), but keeps |keep_alive| streams alive.
   void CloseIdleStreams(size_t keep_alive);
 
+  void StopPhysicalStream(AudioOutputStream* stream);
+
   size_t idle_proxies_;
   std::vector<AudioOutputStream*> idle_streams_;
 
   // When streams are stopped they're added to |idle_streams_|, if no stream is
   // reused before |close_delay_| elapses |close_timer_| will run
   // CloseIdleStreams().
   base::DelayTimer close_timer_;
 
   typedef std::map<AudioOutputProxy*, AudioOutputStream*> AudioStreamMap;
   AudioStreamMap proxy_to_physical_map_;
 
   std::unique_ptr<AudioLog> audio_log_;
   typedef std::map<AudioOutputStream*, int> AudioStreamIDMap;
   AudioStreamIDMap audio_stream_ids_;
   int audio_stream_id_;
 
+  base::WeakPtrFactory<AudioOutputDispatcherImpl> weak_factory_;
   DISALLOW_COPY_AND_ASSIGN(AudioOutputDispatcherImpl);
 };
 
 }  // namespace media
 
 #endif  // MEDIA_AUDIO_AUDIO_OUTPUT_DISPATCHER_IMPL_H_