WebMediaPlayerImpl needs to own the audio source provider.

webkit/media/webmediaplayer_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.
 
 // Delegate calls from WebCore::MediaPlayerPrivate to Chrome's video player.
 // It contains Pipeline which is the actual media player pipeline, it glues
 // the media player pipeline, data source, audio renderer and renderer.
 // Pipeline would creates multiple threads and access some public methods
 // of this class, so we need to be extra careful about concurrent access of
 // methods and members.
@@ skipping 56 matching lines @@
 
 class RenderAudioSourceProvider;
 
 namespace WebKit {
 class WebAudioSourceProvider;
 class WebFrame;
 }
 
 namespace media {
 class MediaLog;
+class AudioRendererSink;

[scherkus (not reviewing), 2012/07/09 23:13:23]

a->z ordering

[Raymond Toy, 2012/07/10 02:51:39]

Done.

 }
 
 namespace webkit_media {
 
 class MediaStreamClient;
 class WebMediaPlayerDelegate;
 class WebMediaPlayerProxy;
 
 class WebMediaPlayerImpl
     : public WebKit::WebMediaPlayer,
       public MessageLoop::DestructionObserver,
       public base::SupportsWeakPtr<WebMediaPlayerImpl> {
  public:
   // Construct a WebMediaPlayerImpl with reference to the client, and media
   // filter collection. By providing the filter collection the implementor can
   // provide more specific media filters that does resource loading and
   // rendering.
   //
   // WebMediaPlayerImpl comes packaged with the following media filters:
   //   - URL fetching
   //   - Demuxing
   //   - Software audio/video decoding
   //   - Video rendering
   //
   // Clients are expected to add their platform-specific audio rendering media
   // filter if they wish to hear any sound coming out the speakers, otherwise
   // audio data is discarded and media plays back based on wall clock time.
   //
+  // When calling this, the audio_source_provider and
+  // audio_renderer_sink arguments should be the same object.

[scherkus (not reviewing), 2012/07/09 23:13:23]

add || around variable names referenced in comments

add a TODO(scherkus) saying "Remove WebAudioSourceProvider parameter once we
refactor RenderAudioSourceProvider to live under webkit/media/ instead of
content/renderer/, see http://crbug.com/136442"

[Raymond Toy, 2012/07/10 02:51:39]

Done.

   WebMediaPlayerImpl(WebKit::WebFrame* frame,
                      WebKit::WebMediaPlayerClient* client,
                      base::WeakPtr<WebMediaPlayerDelegate> delegate,
                      media::FilterCollection* collection,
                      WebKit::WebAudioSourceProvider* audio_source_provider,
+                     media::AudioRendererSink* audio_renderer_sink,
                      media::MessageLoopFactory* message_loop_factory,
                      MediaStreamClient* media_stream_client,
                      media::MediaLog* media_log);
   virtual ~WebMediaPlayerImpl();
 
   virtual void load(const WebKit::WebURL& url, CORSMode cors_mode);
   virtual void cancelLoad();
 
   // Playback controls.
   virtual void play();
@@ skipping 210 matching lines @@
   scoped_refptr<media::MediaLog> media_log_;
 
   // Since accelerated compositing status is only known after the first layout,
   // we delay reporting it to UMA until that time.
   bool accelerated_compositing_reported_;
 
   bool incremented_externally_allocated_memory_;
 
   WebKit::WebAudioSourceProvider* audio_source_provider_;
 
+  // We need to own the audio_renderer_sink to prevent the sink from
+  // getting deleted before we are finished with it.  This should be
+  // the same as audio_source_provider_.

[scherkus (not reviewing), 2012/07/09 23:13:23]

I'd remove the comment -- it's OK to assume this class should hold onto a
pointer (i.e,. this comment will quickly become stale)

In fact it's better to DCHECK this inside the .cc + comment there

[Raymond Toy, 2012/07/10 02:51:39]

Comment removed.  But see comment for .cc where we can't DCHECK_EQ the pointers.

+  scoped_refptr<media::AudioRendererSink> audio_renderer_sink_;
+
   bool is_local_source_;
 
   DISALLOW_COPY_AND_ASSIGN(WebMediaPlayerImpl);
 };
 
 }  // namespace webkit_media
 
 #endif  // WEBKIT_MEDIA_WEBMEDIAPLAYER_IMPL_H_