MediaStream should fire ended event when all tracks are ended

Source/WebCore/Modules/mediastream/MediaStreamTrack.h

 /*
  * Copyright (C) 2011 Google Inc. All rights reserved.
  * Copyright (C) 2011 Ericsson AB. All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions
  * are met:
  * 1.  Redistributions of source code must retain the above copyright
  *     notice, this list of conditions and the following disclaimer.
  * 2.  Redistributions in binary form must reproduce the above copyright
@@ skipping 21 matching lines @@
 #include "EventTarget.h"
 #include "MediaStreamDescriptor.h"
 #include "MediaStreamSource.h"
 #include <wtf/RefCounted.h>
 #include <wtf/RefPtr.h>
 #include <wtf/Vector.h>
 #include <wtf/text/WTFString.h>
 
 namespace WebCore {
 
+class MediaStream;
 class MediaStreamComponent;
 
 class MediaStreamTrack : public RefCounted<MediaStreamTrack>, public ActiveDOMObject, public EventTarget, public MediaStreamSource::Observer {
 public:
-    static PassRefPtr<MediaStreamTrack> create(ScriptExecutionContext*, MediaStreamComponent*);
+    static PassRefPtr<MediaStreamTrack> create(ScriptExecutionContext*, MediaStreamComponent*, MediaStream*);
     virtual ~MediaStreamTrack();
 
     String kind() const;
     String id() const;
     String label() const;
 
     bool enabled() const;
     void setEnabled(bool);
 
     String readyState() const;
 
     DEFINE_ATTRIBUTE_EVENT_LISTENER(mute);
     DEFINE_ATTRIBUTE_EVENT_LISTENER(unmute);
     DEFINE_ATTRIBUTE_EVENT_LISTENER(ended);
 
     MediaStreamComponent* component();
     bool ended() const;
 
     // EventTarget
     virtual const AtomicString& interfaceName() const OVERRIDE;
     virtual ScriptExecutionContext* scriptExecutionContext() const OVERRIDE;
 
     // ActiveDOMObject
     virtual void stop() OVERRIDE;
 
     using RefCounted<MediaStreamTrack>::ref;
     using RefCounted<MediaStreamTrack>::deref;
 
 private:
-    MediaStreamTrack(ScriptExecutionContext*, MediaStreamComponent*);
+    MediaStreamTrack(ScriptExecutionContext*, MediaStreamComponent*, MediaStream*);
 
     // EventTarget
     virtual EventTargetData* eventTargetData() OVERRIDE;
     virtual EventTargetData* ensureEventTargetData() OVERRIDE;
     virtual void refEventTarget() OVERRIDE { ref(); }
     virtual void derefEventTarget() OVERRIDE { deref(); }
     EventTargetData m_eventTargetData;
 
     // MediaStreamSourceObserver
     virtual void sourceChangedState() OVERRIDE;
 
     bool m_stopped;
     RefPtr<MediaStreamComponent> m_component;
+    MediaStream* m_stream;

[abarth-chromium, 2013/04/08 06:24:21]

What's the ownership relationship between MediaStreamTrack and m_stream?  They
both appear to be refcounted, so it's not clear to me what prevents m_stream
from pointing to freed memory.

 };
 
 typedef Vector<RefPtr<MediaStreamTrack> > MediaStreamTrackVector;
 
 } // namespace WebCore
 
 #endif // ENABLE(MEDIA_STREAM)
 
 #endif // MediaStreamTrack_h