1. DomName('MediaStream.getTrackById')
  2. DocsEditable()
MediaStreamTrack getTrackById(String trackId)

Source 

@DomName('MediaStream.getTrackById')
@DocsEditable()
MediaStreamTrack getTrackById(String trackId) => _blink.BlinkMediaStream.instance.getTrackById_Callback_1_(this, trackId);