Oilpan: eagerly sweep some mediasource and mediastream objects.

Source/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 70 matching lines @@
 
     // EventTarget
     virtual const AtomicString& interfaceName() const override;
     virtual ExecutionContext* executionContext() const override;
 
     // ActiveDOMObject
     virtual void stop() override;
 
     PassOwnPtr<AudioSourceProvider> createWebAudioSource();
 
+    // Oilpan: need to eagerly unregister as observer.

[haraken, 2015/06/04 01:06:56]

FYI, this should be fixed by https://codereview.chromium.org/552653005. The CL
was reverted and I didn't have a bandwidth to rework on it...

[sof, 2015/06/04 06:18:03]

I'd completely forgotten about that effort.. I created
https://code.google.com/p/chromium/issues/detail?id=496535 so as to not to lose
track of it.

+    EAGERLY_FINALIZE();
     DECLARE_VIRTUAL_TRACE();
 
 private:
     MediaStreamTrack(ExecutionContext*, MediaStreamComponent*);
 
     // MediaStreamSourceObserver
     virtual void sourceChangedState() override;
 
     void propagateTrackEnded();
 
     MediaStreamSource::ReadyState m_readyState;
     HeapHashSet<Member<MediaStream>> m_registeredMediaStreams;
     bool m_isIteratingRegisteredMediaStreams;
     bool m_stopped;
     RefPtr<MediaStreamComponent> m_component;
 };
 
 typedef HeapVector<Member<MediaStreamTrack>> MediaStreamTrackVector;
 
 } // namespace blink
 
 #endif // MediaStreamTrack_h