The existing heuristic misses some background videos, and not all ads are initially muted, so always require a user gesture to automatically start playing to AppleTV.
Created attachment 258113 [details]
Comment on attachment 258113 [details]
Clearing flags on attachment: 258113
Committed r187776: <http://trac.webkit.org/changeset/187776>
All reviewed patches have been landed. Closing bug.