Fixing scenario where track is rejected and later un-rejected.

talk/app/webrtc/mediastreamsignaling.cc

 /*
  * libjingle
  * Copyright 2012 Google Inc.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions are met:
  *
  *  1. Redistributions of source code must retain the above copyright notice,
  *     this list of conditions and the following disclaimer.
  *  2. Redistributions in binary form must reproduce the above copyright notice,
@@ skipping 508 matching lines @@
   MaybeCreateDefaultStream();
 }
 
 void MediaStreamSignaling::OnLocalDescriptionChanged(
     const SessionDescriptionInterface* desc) {
   const cricket::ContentInfo* audio_content =
       GetFirstAudioContent(desc->description());
   if (audio_content) {
     if (audio_content->rejected) {
       RejectRemoteTracks(cricket::MEDIA_TYPE_AUDIO);
+    } else {
+      AcceptRemoteTracks(cricket::MEDIA_TYPE_AUDIO);
     }
     const cricket::AudioContentDescription* audio_desc =
         static_cast<const cricket::AudioContentDescription*>(
             audio_content->description);
     UpdateLocalTracks(audio_desc->streams(), audio_desc->type());
   }
 
   const cricket::ContentInfo* video_content =
       GetFirstVideoContent(desc->description());
   if (video_content) {
     if (video_content->rejected) {
       RejectRemoteTracks(cricket::MEDIA_TYPE_VIDEO);
+    } else {
+      AcceptRemoteTracks(cricket::MEDIA_TYPE_VIDEO);
     }
     const cricket::VideoContentDescription* video_desc =
         static_cast<const cricket::VideoContentDescription*>(
             video_content->description);
     UpdateLocalTracks(video_desc->streams(), video_desc->type());
   }
 
   const cricket::ContentInfo* data_content =
       GetFirstDataContent(desc->description());
   if (data_content) {
@@ skipping 145 matching lines @@
       VideoTrackInterface* track = stream->FindVideoTrack(info.track_id);
       // There's no guarantee the track is still available, e.g. the track may
       // have been removed from the stream by javascript.
       if (track) {
         track->set_state(webrtc::MediaStreamTrackInterface::kEnded);
       }
     }
   }
 }
 
+void MediaStreamSignaling::AcceptRemoteTracks(cricket::MediaType media_type) {

[pthatcher1, 2015/07/08 20:45:32]

Can you avoid duplication by making a helper method, something like
SetStateOfRemoteTracks?

Then you could just do 

SetStateOfRemoteTracks(media_type, webrtc::MediaStreamTrackInterface::kLive);

and

SetStateOfRemoteTracks(media_type, webrtc::MediaStreamTrackInterface::kEnded);

[Taylor Brandstetter, 2015/07/08 23:04:03]

Sure, that should be fine as long as accepting/rejecting remote tracks never
requires more than changing the state.

+  TrackInfos* current_tracks = GetRemoteTracks(media_type);
+  for (TrackInfos::iterator track_it = current_tracks->begin();
+       track_it != current_tracks->end(); ++track_it) {
+    const TrackInfo& info = *track_it;
+    MediaStreamInterface* stream = remote_streams_->find(info.stream_label);
+    if (media_type == cricket::MEDIA_TYPE_AUDIO) {
+      AudioTrackInterface* track = stream->FindAudioTrack(info.track_id);
+      if (track) {
+        track->set_state(webrtc::MediaStreamTrackInterface::kLive);
+      }
+    }
+    if (media_type == cricket::MEDIA_TYPE_VIDEO) {
+      VideoTrackInterface* track = stream->FindVideoTrack(info.track_id);
+      if (track) {
+        track->set_state(webrtc::MediaStreamTrackInterface::kLive);
+      }
+    }
+  }
+}
+
 void MediaStreamSignaling::UpdateEndedRemoteMediaStreams() {
   std::vector<scoped_refptr<MediaStreamInterface> > streams_to_remove;
   for (size_t i = 0; i < remote_streams_->count(); ++i) {
     MediaStreamInterface*stream = remote_streams_->at(i);
     if (stream->GetAudioTracks().empty() && stream->GetVideoTracks().empty()) {
       streams_to_remove.push_back(stream);
     }
   }
 
   std::vector<scoped_refptr<MediaStreamInterface> >::const_iterator it;
@@ skipping 305 matching lines @@
 int MediaStreamSignaling::FindDataChannelBySid(int sid) const {
   for (size_t i = 0; i < sctp_data_channels_.size(); ++i) {
     if (sctp_data_channels_[i]->id() == sid) {
       return static_cast<int>(i);
     }
   }
   return -1;
 }
 
 }  // namespace webrtc