Bug 1425873 - Part 2: Sync send stream ids even when there is no send track. r+drno r=drno

MozReview-Commit-ID: 7s3f1Q8sCI1

--HG--
extra : rebase_source : a3c0446e31cff547b8277c8811de2e5e0967de93

media/webrtc/signaling/src/peerconnection/TransceiverImpl.cpp

@@ -417,30 +417,32 @@ TransceiverImpl::SyncWithJS(dom::RTCRtpTransceiver& aJsTransceiver,
     return;
   }
 
+  std::string trackId = mJsepTransceiver->mSendTrack.GetTrackId();
+
   if (sendTrack) {
     nsString wideTrackId;
     sendTrack->GetId(wideTrackId);
-    std::string trackId = NS_ConvertUTF16toUTF8(wideTrackId).get();
+    trackId = NS_ConvertUTF16toUTF8(wideTrackId).get();
     MOZ_ASSERT(!trackId.empty());
-
-    nsTArray<RefPtr<DOMMediaStream>> streams;
-    sender->GetStreams(streams, aRv);
-    if (aRv.Failed()) {
-      return;
-    }
-
-    std::vector<std::string> streamIds;
-    for (const auto& stream : streams) {
-      nsString wideStreamId;
-      stream->GetId(wideStreamId);
-      std::string streamId = NS_ConvertUTF16toUTF8(wideStreamId).get();
-      MOZ_ASSERT(!streamId.empty());
-      streamIds.push_back(streamId);
-    }
-
-    mJsepTransceiver->mSendTrack.UpdateTrackIds(streamIds, trackId);
   }
 
+  nsTArray<RefPtr<DOMMediaStream>> streams;
+  sender->GetStreams(streams, aRv);
+  if (aRv.Failed()) {
+    return;
+  }
+
+  std::vector<std::string> streamIds;
+  for (const auto& stream : streams) {
+    nsString wideStreamId;
+    stream->GetId(wideStreamId);
+    std::string streamId = NS_ConvertUTF16toUTF8(wideStreamId).get();
+    MOZ_ASSERT(!streamId.empty());
+    streamIds.push_back(streamId);
+  }
+
+  mJsepTransceiver->mSendTrack.UpdateTrackIds(streamIds, trackId);
+
   // Update RTCRtpParameters
   // TODO: Both ways for things like ssrc, codecs, header extensions, etc