Only allow one tab at a time to capture media.
Created attachment 307510 [details] Proposed patch.
<rdar://problem/31717891>
Created attachment 307511 [details] Patch for landing.
Comment on attachment 307511 [details] Patch for landing. Clearing flags on attachment: 307511 Committed r215537: <http://trac.webkit.org/changeset/215537>
All reviewed patches have been landed. Closing bug.