r183221 disabled QTKit by default on some version of OS X. Because AVFoundation is always disabled by default, no media engine is enabled until Settings are updated. Fix this by enabling AVFoundation by default on the versions where QTKit is disabled by default.
<rdar://problem/21165315>
Created attachment 254496 [details] Proposed patch.
Comment on attachment 254496 [details] Proposed patch. Clearing flags on attachment: 254496 Committed r185333: <http://trac.webkit.org/changeset/185333>
All reviewed patches have been landed. Closing bug.