Implement HTMLMediaElement::srcObject.

Source/modules/mediastream/MediaStream.cpp

Index: Source/modules/mediastream/MediaStream.cpp
diff --git a/Source/modules/mediastream/MediaStream.cpp b/Source/modules/mediastream/MediaStream.cpp
index 86ffd4fea04c9bc0b58388124190c96065b1f3af..e5a53fd916f004246ae7efade4385baad6900927 100644
--- a/Source/modules/mediastream/MediaStream.cpp
+++ b/Source/modules/mediastream/MediaStream.cpp
@@ -27,6 +27,9 @@
 #include "modules/mediastream/MediaStream.h"
 
 #include "bindings/core/v8/ExceptionState.h"
+#include "bindings/core/v8/ScriptValue.h"
+#include "bindings/modules/v8/V8MediaStream.h"
+#include "core/dom/DOMURL.h"
 #include "core/dom/ExceptionCode.h"
 #include "modules/mediastream/MediaStreamRegistry.h"
 #include "modules/mediastream/MediaStreamTrackEvent.h"
@@ -54,6 +57,13 @@ static void processTrack(MediaStreamTrack* track, MediaStreamTrackVector& trackV
         trackVector.append(track);
 }
 
+static MediaProvider* MediaProviderConverter(const ScriptValue& value)
+{
+    v8::Handle<v8::Value> v8Value(value.v8Value());
+    MediaStream* stream = V8MediaStream::toImplWithTypeCheck(value.isolate(), v8Value);

[sof, 2014/09/19 06:26:23]

return V8MediaStream::toImplWithTypeCheck(value.isolate(), v8Value);

[perkj_chrome, 2014/09/19 10:48:06]

Done.

+    return stream;
+}
+
 MediaStream* MediaStream::create(ExecutionContext* context)
 {
     MediaStreamTrackVector audioTracks;
@@ -95,7 +105,8 @@ MediaStream* MediaStream::create(ExecutionContext* context, PassRefPtr<MediaStre
 }
 
 MediaStream::MediaStream(ExecutionContext* context, PassRefPtr<MediaStreamDescriptor> streamDescriptor)
-    : ContextLifecycleObserver(context)
+    : MediaProvider(EventTargetNames::MediaStream, bind<const ScriptValue&>(MediaProviderConverter))
+    , ContextLifecycleObserver(context)
     , m_stopped(false)
     , m_descriptor(streamDescriptor)
     , m_scheduledEventTimer(this, &MediaStream::scheduledEventTimerFired)
@@ -120,7 +131,8 @@ MediaStream::MediaStream(ExecutionContext* context, PassRefPtr<MediaStreamDescri
 }
 
 MediaStream::MediaStream(ExecutionContext* context, const MediaStreamTrackVector& audioTracks, const MediaStreamTrackVector& videoTracks)
-    : ContextLifecycleObserver(context)
+    : MediaProvider(EventTargetNames::MediaStream, bind<const ScriptValue&>(MediaProviderConverter))
+    , ContextLifecycleObserver(context)
     , m_stopped(false)
     , m_scheduledEventTimer(this, &MediaStream::scheduledEventTimerFired)
 {
@@ -147,6 +159,8 @@ MediaStream::MediaStream(ExecutionContext* context, const MediaStreamTrackVector
 
 MediaStream::~MediaStream()
 {
+    if (!m_objectUrl.isEmpty())
+        DOMURL::revokeObjectURL(executionContext(), m_objectUrl);

[sof, 2014/09/19 06:26:23]

(It'd be nice to have an auto-revocation public URL abstraction that handled
this on destruction.)

[perkj_chrome, 2014/09/19 10:48:06]

Sure, 
Would that make sence even if we refactor MediaProvider to not use urls later?
Is there another use case as well?

[sof, 2014/09/19 13:06:11]

Certainly, this wasn't meant as an actionable issue for this CL, just thinking
of ways to avoid having to remember to perform the revocation step.

     m_descriptor->setClient(0);
 }
 
@@ -387,11 +401,19 @@ URLRegistry& MediaStream::registry() const
     return MediaStreamRegistry::registry();
 }
 
+const String& MediaStream::getObjectUrl()
+{
+    if (m_objectUrl.isEmpty())
+        m_objectUrl = DOMURL::createPublicURL(executionContext(), this);
+    return m_objectUrl;
+}
+
 void MediaStream::trace(Visitor* visitor)
 {
     visitor->trace(m_audioTracks);
     visitor->trace(m_videoTracks);
     visitor->trace(m_scheduledEvents);
+    MediaProvider::trace(visitor);
     EventTargetWithInlineData::trace(visitor);
 }