Oilpan: Move MediaStreamSource, MediaStreamComponent and MediaStreamDescriptor to oilpan's heap

Source/platform/mediastream/MediaStreamSource.cpp

Index: Source/platform/mediastream/MediaStreamSource.cpp
diff --git a/Source/platform/mediastream/MediaStreamSource.cpp b/Source/platform/mediastream/MediaStreamSource.cpp
index 6f69127bc64d616f444bbabfb7a2495a657f13a7..9324c48c959a895a66eae40478f2e7c02150dd05 100644
--- a/Source/platform/mediastream/MediaStreamSource.cpp
+++ b/Source/platform/mediastream/MediaStreamSource.cpp
@@ -34,9 +34,36 @@
 
 namespace blink {
 
-PassRefPtr<MediaStreamSource> MediaStreamSource::create(const String& id, Type type, const String& name, ReadyState readyState, bool requiresConsumer)
+// The disposer pattern actually makes the deletion of the extra data happen
+// earlier and not later. The disposer makes sure that the extra data is
+// destructed in weak processing which is run before sweeping and therefore
+// all the objects are still alive and can be touched.
+//
+// FIXME: Oilpan: This disposer pattern is duplicated in a lot of places.
+// We should create a good abstraction class for this and remove the code duplication.
+class MediaStreamSourceDisposer {
+public:
+    explicit MediaStreamSourceDisposer(MediaStreamSource& source) : m_source(source) { }
+    ~MediaStreamSourceDisposer()
+    {
+        m_source.dispose();
+    }
+
+private:
+    MediaStreamSource& m_source;
+};
+
+typedef HeapHashMap<WeakMember<MediaStreamSource>, OwnPtr<MediaStreamSourceDisposer> > SourceDisposers;
+
+static SourceDisposers& sourceDisposers()
 {
-    return adoptRef(new MediaStreamSource(id, type, name, readyState, requiresConsumer));
+    DEFINE_STATIC_LOCAL(Persistent<SourceDisposers>, disposers, (new SourceDisposers));
+    return *disposers;
+}
+
+MediaStreamSource* MediaStreamSource::create(const String& id, Type type, const String& name, ReadyState readyState, bool requiresConsumer)
+{
+    return new MediaStreamSource(id, type, name, readyState, requiresConsumer);
 }
 
 MediaStreamSource::MediaStreamSource(const String& id, Type type, const String& name, ReadyState readyState, bool requiresConsumer)
@@ -46,27 +73,27 @@ MediaStreamSource::MediaStreamSource(const String& id, Type type, const String&
     , m_readyState(readyState)
     , m_requiresConsumer(requiresConsumer)
 {
+    sourceDisposers().add(this, adoptPtr(new MediaStreamSourceDisposer(*this)));
+}
+
+void MediaStreamSource::dispose()
+{
+    m_extraData = nullptr;
 }
 
 void MediaStreamSource::setReadyState(ReadyState readyState)
 {
     if (m_readyState != ReadyStateEnded && m_readyState != readyState) {
         m_readyState = readyState;
-        for (Vector<Observer*>::iterator i = m_observers.begin(); i != m_observers.end(); ++i)
+        for (HeapHashSet<WeakMember<Observer> >::iterator i = m_observers.begin(); i != m_observers.end(); ++i)
             (*i)->sourceChangedState();
     }
 }
 
 void MediaStreamSource::addObserver(MediaStreamSource::Observer* observer)
 {
-    m_observers.append(observer);
-}
-
-void MediaStreamSource::removeObserver(MediaStreamSource::Observer* observer)
-{
-    size_t pos = m_observers.find(observer);
-    if (pos != kNotFound)
-        m_observers.remove(pos);
+    ASSERT(!m_observers.contains(observer));
+    m_observers.add(observer);
 }
 
 void MediaStreamSource::addAudioConsumer(AudioDestinationConsumer* consumer)
@@ -103,4 +130,11 @@ void MediaStreamSource::consumeAudio(AudioBus* bus, size_t numberOfFrames)
         (*it)->consumeAudio(bus, numberOfFrames);
 }
 
+void MediaStreamSource::trace(Visitor* visitor)
+{
+    visitor->trace(m_observers);
+    visitor->trace(m_audioConsumers);
+}
+
 } // namespace blink
+