Don't collect 'other tracks' in HTMLMediaElement::configureTextTracks

Don't collect 'other tracks' in HTMLMediaElement::configureTextTracks

After having processed 'subtitles', 'captions', 'descriptions' and
'chapters' tracks, there's only 'metadata' tracks left (no more kinds are
currently defined). This means that the 'otherTracks' set will always be
empty. Remove it an add an assert.

Also take the opportunity to rename the various methods involved to match
the match the names of the spec. algorithms they implement.

 configureTextTracks -> honorUserPreferencesForAutomaticTextTrackSelection
 configureTextTrackGroup -> performAutomaticTextTrackSelection
 configureMetadataTextTrackGroup -> enableDefaultMetadataTextTracks

Committed: https://src.chromium.org/viewvc/blink?view=rev&revision=189262

[fs, 2015-01-30 13:31:07]

fs@opera.com changed reviewers:
+ philipj@opera.com

[fs, 2015-01-30 13:32:32]

Hope you like the new names! =D

[philipj_slow, 2015-01-30 15:29:53]

The CQ bit was checked by philipj@opera.com

[philipj_slow, 2015-01-30 15:29:53]

lgtm

They're delightful!

[commit-bot: I haz the power, 2015-01-30 15:30:15]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/891733002/1

[commit-bot: I haz the power, 2015-01-30 16:05:36]

Committed patchset #1 (id:1) as
https://src.chromium.org/viewvc/blink?view=rev&revision=189262