--- a/dom/media/MediaManager.cpp
+++ b/dom/media/MediaManager.cpp
@@ -3372,16 +3372,18 @@ SourceListener::SourceListener()
   , mMainThreadCheck(nullptr)
   , mPrincipalHandle(PRINCIPAL_HANDLE_NONE)
   , mWindowListener(nullptr)
 {}
 
 void
 SourceListener::Register(GetUserMediaWindowListener* aListener)
 {
+  LOG(("SourceListener %p registering with window listener %p", this, aListener));
+
   if (mWindowListener) {
     MOZ_ASSERT(false, "Already registered");
     return;
   }
   if (mActivated) {
     MOZ_ASSERT(false, "Already activated");
     return;
   }
@@ -3395,16 +3397,18 @@ SourceListener::Register(GetUserMediaWin
 
 void
 SourceListener::Activate(SourceMediaStream* aStream,
                          AudioDevice* aAudioDevice,
                          VideoDevice* aVideoDevice)
 {
   MOZ_ASSERT(NS_IsMainThread(), "Only call on main thread");
 
+  LOG(("SourceListener %p activating audio=%p video=%p", this, aAudioDevice, aVideoDevice));
+
   if (mActivated) {
     MOZ_ASSERT(false, "Already activated");
     return;
   }
 
   mActivated = true;
   mMainThreadCheck = PR_GetCurrentThread();
   mStream = aStream;
@@ -3417,16 +3421,18 @@ void
 SourceListener::Stop()
 {
   MOZ_ASSERT(NS_IsMainThread(), "Only call on main thread");
 
   if (mStopped) {
     return;
   }
 
+  LOG(("SourceListener %p stopping", this));
+
   // StopSharing() has some special logic, at least for audio capture.
   // It must be called when all tracks have stopped, before setting mStopped.
   StopSharing();
 
   mStopped = true;
 
   if (mAudioDevice && !mAudioStopped) {
     StopTrack(kAudioTrack);
@@ -3444,17 +3450,17 @@ SourceListener::Stop()
 void
 SourceListener::Remove()
 {
   MOZ_ASSERT(NS_IsMainThread());
   if (!mStream || mRemoved) {
     return;
   }
 
-  LOG(("SourceListener removed on purpose, mFinished = %d", (int) mFinished));
+  LOG(("SourceListener %p removed on purpose, mFinished = %d", this, (int) mFinished));
   mRemoved = true; // RemoveListener is async, avoid races
   mWindowListener = nullptr;
 
   // If it's destroyed, don't call - listener will be removed and we'll be notified!
   if (!mStream->IsDestroyed()) {
     mStream->RemoveListener(this);
   }
 }
@@ -3464,30 +3470,32 @@ SourceListener::StopTrack(TrackID aTrack
 {
   MOZ_ASSERT(NS_IsMainThread(), "Only call on main thread");
 
   RefPtr<MediaDevice> device;
   RefPtr<SourceMediaStream> source;
 
   switch (aTrackID) {
     case kAudioTrack: {
+      LOG(("SourceListener %p stopping audio track %d", this, aTrackID));
       if (!mAudioDevice) {
         NS_ASSERTION(false, "Can't stop audio. No device.");
         return;
       }
       if (mAudioStopped) {
         // Audio already stopped
         return;
       }
       device = mAudioDevice;
       source = GetSourceStream();
       mAudioStopped = true;
       break;
     }
     case kVideoTrack: {
+      LOG(("SourceListener %p stopping video track %d", this, aTrackID));
       if (!mVideoDevice) {
         NS_ASSERTION(false, "Can't stop video. No device.");
         return;
       }
       if (mVideoStopped) {
         // Video already stopped
         return;
       }
@@ -3504,16 +3512,17 @@ SourceListener::StopTrack(TrackID aTrack
 
   MediaManager::PostTask(NewTaskFrom([device, source, aTrackID]() {
     device->GetSource()->Stop(source, aTrackID);
     device->Deallocate();
   }));
 
   if ((!mAudioDevice || mAudioStopped) &&
       (!mVideoDevice || mVideoStopped)) {
+    LOG(("SourceListener %p this was the last track stopped", this));
     Stop();
   }
 
   if (!mWindowListener) {
     MOZ_ASSERT(false, "Should still have window listener");
     return;
   }
   mWindowListener->NotifySourceTrackStopped();
@@ -3524,16 +3533,18 @@ SourceListener::StopSharing()
 {
   MOZ_ASSERT(NS_IsMainThread());
   MOZ_RELEASE_ASSERT(mWindowListener);
 
   if (mStopped) {
     return;
   }
 
+  LOG(("SourceListener %p StopSharing", this));
+
   if (mVideoDevice &&
       (mVideoDevice->GetMediaSource() == MediaSourceEnum::Screen ||
        mVideoDevice->GetMediaSource() == MediaSourceEnum::Application ||
        mVideoDevice->GetMediaSource() == MediaSourceEnum::Window)) {
     // We want to stop the whole stream if there's no audio;
     // just the video track if we have both.
     // StopTrack figures this out for us.
     StopTrack(kVideoTrack);
@@ -3649,16 +3660,18 @@ SourceListener::NotifyFinished()
 {
   MOZ_ASSERT(NS_IsMainThread());
   mFinished = true;
   if (!mWindowListener) {
     // Removed explicitly before finished.
     return;
   }
 
+  LOG(("SourceListener %p NotifyFinished", this));
+
   Stop(); // we know it's been activated
   mWindowListener->Remove(this);
 }
 
 void
 SourceListener::NotifyRemoved()
 {
   MOZ_ASSERT(NS_IsMainThread());