Return early in automaticTrackSelectionForUpdatedUserPreference()

Return early in automaticTrackSelectionForUpdatedUserPreference()

If there are no text tracks, nothing in the method does anything,
except updateTextTrackDisplay() which will create the text track
container which is not needed yet.

BUG=457850
Committed: https://src.chromium.org/viewvc/blink?view=rev&revision=198767

[philipj_slow, 2015-07-13 09:07:15]

The CQ bit was checked by philipj@opera.com to run a CQ dry run

[commit-bot: I haz the power, 2015-07-13 09:07:23]

Dry run: CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/1228293003/1

[commit-bot: I haz the power, 2015-07-13 10:36:02]

The CQ bit was unchecked by commit-bot@chromium.org

[commit-bot: I haz the power, 2015-07-13 10:36:03]

Dry run: This issue passed the CQ dry run.

[philipj_slow, 2015-07-13 10:54:39]

philipj@opera.com changed reviewers:
+ fs@opera.com, sigbjornf@opera.se

[philipj_slow, 2015-07-13 10:54:40]

PTAL

[fs, 2015-07-13 11:01:04]

Right, I was thinking this too...

LGTM

[philipj_slow, 2015-07-13 11:12:37]

The CQ bit was checked by philipj@opera.com

[commit-bot: I haz the power, 2015-07-13 11:12:45]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/1228293003/1

[commit-bot: I haz the power, 2015-07-13 11:16:08]

Committed patchset #1 (id:1) as
https://src.chromium.org/viewvc/blink?view=rev&revision=198767