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

Source/platform/mediastream/MediaStreamComponent.cpp

Index: Source/platform/mediastream/MediaStreamComponent.cpp
diff --git a/Source/platform/mediastream/MediaStreamComponent.cpp b/Source/platform/mediastream/MediaStreamComponent.cpp
index 43bc57d0c4d4148621eedb36f73676f052e7c74a..31fa69830641c459fc429f3550ef26a73709b87e 100644
--- a/Source/platform/mediastream/MediaStreamComponent.cpp
+++ b/Source/platform/mediastream/MediaStreamComponent.cpp
@@ -40,23 +40,56 @@
 
 namespace blink {
 
-PassRefPtr<MediaStreamComponent> MediaStreamComponent::create(PassRefPtr<MediaStreamSource> source)
+MediaStreamComponent* MediaStreamComponent::create(MediaStreamSource* source)
 {
-    return adoptRef(new MediaStreamComponent(createCanonicalUUIDString(), source));
+    return new MediaStreamComponent(createCanonicalUUIDString(), source);
 }
 
-PassRefPtr<MediaStreamComponent> MediaStreamComponent::create(const String& id, PassRefPtr<MediaStreamSource> source)
+MediaStreamComponent* MediaStreamComponent::create(const String& id, MediaStreamSource* source)
 {
-    return adoptRef(new MediaStreamComponent(id, source));
+    return new MediaStreamComponent(id, source);
 }
 
-MediaStreamComponent::MediaStreamComponent(const String& id, PassRefPtr<MediaStreamSource> source)
+// 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 MediaStreamComponentDisposer {
+public:
+    explicit MediaStreamComponentDisposer(MediaStreamComponent& component) : m_component(component) { }
+    ~MediaStreamComponentDisposer()
+    {
+        m_component.dispose();
+    }
+
+private:
+    MediaStreamComponent& m_component;
+};
+
+typedef HeapHashMap<WeakMember<MediaStreamComponent>, OwnPtr<MediaStreamComponentDisposer> > ComponentDisposers;
+
+static ComponentDisposers& componentDisposers()
+{
+    DEFINE_STATIC_LOCAL(Persistent<ComponentDisposers>, disposers, (new ComponentDisposers));
+    return *disposers;
+}
+
+MediaStreamComponent::MediaStreamComponent(const String& id, MediaStreamSource* source)
     : m_source(source)
     , m_id(id)
     , m_enabled(true)
     , m_muted(false)
 {
     ASSERT(m_id.length());
+    componentDisposers().add(this, adoptPtr(new MediaStreamComponentDisposer(*this)));
+}
+
+void MediaStreamComponent::dispose()
+{
+    m_extraData = nullptr;
 }
 
 #if ENABLE(WEB_AUDIO)
@@ -88,5 +121,10 @@ void MediaStreamComponent::AudioSourceProviderImpl::provideInput(AudioBus* bus,
 }
 #endif // #if ENABLE(WEB_AUDIO)
 
+void MediaStreamComponent::trace(Visitor* visitor)
+{
+    visitor->trace(m_source);
+}
+
 } // namespace blink