Oilpan: have the media element safely close its MediaSource.

Source/modules/mediasource/SourceBuffer.cpp

 /*
  * Copyright (C) 2013 Google Inc. All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions are
  * met:
  *
  *     * Redistributions of source code must retain the above copyright
  * notice, this list of conditions and the following disclaimer.
  *     * Redistributions in binary form must reproduce the above
@@ skipping 87 matching lines @@
     , m_streamMaxSize(0)
     , m_appendStreamAsyncPartRunner(this, &SourceBuffer::appendStreamAsyncPart)
 {
     ASSERT(m_webSourceBuffer);
     ASSERT(m_source);
     ScriptWrappable::init(this);
 }
 
 SourceBuffer::~SourceBuffer()
 {
+#if ENABLE(OILPAN)
+    removedFromMediaSource();

[haraken, 2014/07/03 03:25:37]

Just help me understand: What is this change for?

[sof, 2014/07/03 06:22:24]

If MediaSource and HTMLMediaElement die at the same time, then MediaSource will
not be explicitly closed. This takes care of the lack of such wrt reset'ing the
MediaSource's SourceBuffers.

[haraken, 2014/07/03 06:40:31]

Hmm, in my understanding, SourceBuffers are owned by the MediaSource, so the
SourceBuffers always die with the MediaSource. Then we don't need to call
removedFromMediaSource() in ~SourceBuffer().

[sof, 2014/07/03 06:52:25]

That matches my understanding of ownership (via SourceBufferList.) But close()
(via onReadyStateChange()) will explicitly call removeFromMediaSource() on them,
so if it doesn't, someone else will.

Hmm, looking at all that SourceBuffer::abortIfUpdating() will potentially do,
that's too much - no need to fire events, for instance. Will address that.

+#else
     ASSERT(isRemoved());
+#endif
     ASSERT(!m_loader);
     ASSERT(!m_stream);
 }
 
 const AtomicString& SourceBuffer::segmentsKeyword()
 {
     DEFINE_STATIC_LOCAL(const AtomicString, segments, ("segments", AtomicString::ConstructFromLiteral));
     return segments;
 }
 
@@ skipping 591 matching lines @@
 }
 
 void SourceBuffer::trace(Visitor* visitor)
 {
     visitor->trace(m_source);
     visitor->trace(m_stream);
     EventTargetWithInlineData::trace(visitor);
 }
 
 } // namespace WebCore