Handle empty lines in the 'TimingsAndSettings' state in the WebVTTParser

Handle empty lines in the 'TimingsAndSettings' state in the WebVTTParser

As per the WebVTT parsing specification, step 27 ("If line is the empty
string, then discard cue and jump to the step labeled cue loop."), the
cue should be discarded and the cue loop restarted if an "identifier"
line is followed by an empty line. Transitioning to the 'BadCue' state
will lose the transition, so we need to transition explicitly from the
'TimingsAndSettings' state (to the 'Id' state.)

BUG=314056
Committed: https://src.chromium.org/viewvc/blink?view=rev&revision=161184

[Nate Chapin, 2013-11-01 16:23:14]

lgtm

[commit-bot: I haz the power, 2013-11-01 16:44:05]

CQ is trying da patch. Follow status at
https://chromium-status.appspot.com/cq/fs@opera.com/55853002/1

[commit-bot: I haz the power, 2013-11-01 18:08:40]

Change committed as 161184