Add MediaStream.active attribute

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 7d5caddfc43eeb992c04365b18a6fafb8fda69d2..625fa0cf007fb02bf8af7403b11656530d23c58d 100644
--- a/Source/modules/mediastream/MediaStream.cpp
+++ b/Source/modules/mediastream/MediaStream.cpp
@@ -117,6 +117,11 @@ MediaStream::MediaStream(ExecutionContext* context, PassRefPtr<MediaStreamDescri
         newTrack->registerMediaStream(this);
         m_videoTracks.append(newTrack);
     }
+
+    if (emptyOrOnlyEndedTracks()) {
+        m_descriptor->setEnded();

[perkj_chrome, 2015/01/12 11:22:19]

should setEnded be removed? 

If I understand the spec correctly a MediaStream can now toggle between inactive
and active depending on the track members readyState and what tracks it
contains. So inactive is not the same as ended? 

+        m_descriptor->setActive(false);
+    }
 }
 
 MediaStream::MediaStream(ExecutionContext* context, const MediaStreamTrackVector& audioTracks, const MediaStreamTrackVector& videoTracks)
@@ -143,6 +148,10 @@ MediaStream::MediaStream(ExecutionContext* context, const MediaStreamTrackVector
 
     m_audioTracks = audioTracks;
     m_videoTracks = videoTracks;
+    if (emptyOrOnlyEndedTracks()) {
+        m_descriptor->setEnded();
+        m_descriptor->setActive(false);
+    }
 }
 
 MediaStream::~MediaStream()
@@ -150,6 +159,20 @@ MediaStream::~MediaStream()
     m_descriptor->setClient(0);
 }
 
+bool MediaStream::emptyOrOnlyEndedTracks()
+{
+    if (!m_audioTracks.size() && !m_videoTracks.size()) {
+        return true;
+    }
+    for (MediaStreamTrackVector::iterator iter = m_audioTracks.begin(); iter !=

[perkj_chrome, 2015/01/12 11:22:19]

it looks like this this line is not complete? At least not in the code review
system. 

+        if (!iter->get()->ended())
+            return false;
+    for (MediaStreamTrackVector::iterator iter = m_videoTracks.begin(); iter !=
+        if (!iter->get()->ended())
+            return false;
+    return true;
+}
+
 bool MediaStream::ended() const
 {
     return m_stopped || m_descriptor->ended();
@@ -167,8 +190,8 @@ MediaStreamTrackVector MediaStream::getTracks()
 
 void MediaStream::addTrack(MediaStreamTrack* track, ExceptionState& exceptionState)
 {
-    if (ended()) {
-        exceptionState.throwDOMException(InvalidStateError, "The MediaStream is finished.");
+    if (!active()) {

[perkj_chrome, 2015/01/12 11:22:19]

Adding a track if the state is inactive should toogle the state to active? You
can create an empty MS that should this be inactive. Later adding a track should
change the state to active.

+        exceptionState.throwDOMException(InvalidStateError, "The MediaStream is inactive.");
         return;
     }
 
@@ -195,8 +218,8 @@ void MediaStream::addTrack(MediaStreamTrack* track, ExceptionState& exceptionSta
 
 void MediaStream::removeTrack(MediaStreamTrack* track, ExceptionState& exceptionState)
 {
-    if (ended()) {
-        exceptionState.throwDOMException(InvalidStateError, "The MediaStream is finished.");
+    if (!active()) {
+        exceptionState.throwDOMException(InvalidStateError, "The MediaStream is inactive.");
         return;
     }
 
@@ -224,8 +247,10 @@ void MediaStream::removeTrack(MediaStreamTrack* track, ExceptionState& exception
     track->unregisterMediaStream(this);
     m_descriptor->removeComponent(track->component());
 
-    if (!m_audioTracks.size() && !m_videoTracks.size())
+    if (emptyOrOnlyEndedTracks()) {
         m_descriptor->setEnded();
+        m_descriptor->setActive(false);
+    }
 
     MediaStreamCenter::instance().didRemoveMediaStreamTrack(m_descriptor.get(), track->component());
 }
@@ -282,10 +307,12 @@ void MediaStream::trackEnded()
 
 void MediaStream::streamEnded()
 {
-    if (ended())
+    if (!active())
         return;
 
+    m_descriptor->setActive(false);
     m_descriptor->setEnded();
+    scheduleDispatchEvent(Event::create(EventTypeNames::inactive));
     scheduleDispatchEvent(Event::create(EventTypeNames::ended));
 }
 
@@ -293,6 +320,7 @@ void MediaStream::contextDestroyed()
 {
     ContextLifecycleObserver::contextDestroyed();
     m_stopped = true;
+    m_descriptor->setActive(false);
 }
 
 const AtomicString& MediaStream::interfaceName() const
@@ -308,7 +336,7 @@ ExecutionContext* MediaStream::executionContext() const
 void MediaStream::addRemoteTrack(MediaStreamComponent* component)
 {
     ASSERT(component);
-    if (ended())
+    if (!active())
         return;
 
     MediaStreamTrack* track = MediaStreamTrack::create(executionContext(), component);