Reland: [Oilpan] Move MediaStream{Source|Component|Descriptor} to Oilpan heap

third_party/WebKit/Source/modules/mediastream/MediaStreamTrack.cpp

Index: third_party/WebKit/Source/modules/mediastream/MediaStreamTrack.cpp
diff --git a/third_party/WebKit/Source/modules/mediastream/MediaStreamTrack.cpp b/third_party/WebKit/Source/modules/mediastream/MediaStreamTrack.cpp
index 4b1fe41c63082edce7c7057775782fa25dc4f201..9c8f7c946766e9d46e2600508d2644020323fc63 100644
--- a/third_party/WebKit/Source/modules/mediastream/MediaStreamTrack.cpp
+++ b/third_party/WebKit/Source/modules/mediastream/MediaStreamTrack.cpp
@@ -60,7 +60,6 @@ MediaStreamTrack::MediaStreamTrack(ExecutionContext* context, MediaStreamCompone
 
 MediaStreamTrack::~MediaStreamTrack()
 {
-    m_component->source()->removeObserver(this);
 }
 
 String MediaStreamTrack::kind() const
@@ -163,9 +162,9 @@ void MediaStreamTrack::stopTrack(ExceptionState& exceptionState)
 
 MediaStreamTrack* MediaStreamTrack::clone(ExecutionContext* context)
 {
-    RefPtr<MediaStreamComponent> clonedComponent = MediaStreamComponent::create(component()->source());
-    MediaStreamTrack* clonedTrack = MediaStreamTrack::create(context, clonedComponent.get());
-    MediaStreamCenter::instance().didCreateMediaStreamTrack(clonedComponent.get());
+    MediaStreamComponent* clonedComponent = MediaStreamComponent::create(component()->source());
+    MediaStreamTrack* clonedTrack = MediaStreamTrack::create(context, clonedComponent);
+    MediaStreamCenter::instance().didCreateMediaStreamTrack(clonedComponent);
     return clonedTrack;
 }
 
@@ -205,11 +204,6 @@ void MediaStreamTrack::propagateTrackEnded()
     m_isIteratingRegisteredMediaStreams = false;
 }
 
-MediaStreamComponent* MediaStreamTrack::component()
-{
-    return m_component.get();
-}
-
 void MediaStreamTrack::stop()
 {
     m_stopped = true;
@@ -248,6 +242,7 @@ ExecutionContext* MediaStreamTrack::executionContext() const
 DEFINE_TRACE(MediaStreamTrack)
 {
     visitor->trace(m_registeredMediaStreams);
+    visitor->trace(m_component);
     RefCountedGarbageCollectedEventTargetWithInlineData<MediaStreamTrack>::trace(visitor);
     ActiveDOMObject::trace(visitor);
 }