This API has been deployed to release for some time. There isi
no longer value to being able to quickly disable it.
MozReview-Commit-ID: Jj6CyWzP93g
--HG--
extra : rebase_source : 2dc0547229b53865a4f7cfcf7ca417eb3dec0356
Our JS WebVTT implementation (vtt.js) needs access to a TextTrackList's
MediaElement in order to compute a TextTrackCue's line position. Therefore,
we need to expose it to chrome JS.
Add webidl interfaces and implementations of the HTML <track>
element and related TextTrack, TextTrackList, TextTrackCue,
and TextTrackCueList dom objects.
Visibility is controlled by the media.webvtt.enabled pref,
which defaults to false.
HTMLMediaElement:NewURIFromString() is hoisted to
nsGenericHTMLElement so it's available to the track
element as well.
This patch is primarily work by Dale Karp, David Humphrey
and others as Seneca College.
Ralph Giles
Rick Eyre
Brendan Long
Olli Pettay