An AVPlayerItem's AVAssetTracks become NULL during AirPlay so it is not possible to determine a track's media type. Assume a file has audio when AirPlay is active so we set the correct audio category.
<rdar://problem/24616592>
Created attachment 281990 [details] Proposed patch.
Created attachment 281992 [details] Proposed patch.
Comment on attachment 281992 [details] Proposed patch. Clearing flags on attachment: 281992 Committed r202427: <http://trac.webkit.org/changeset/202427>
All reviewed patches have been landed. Closing bug.