Use VTTScanner for VTT region settings parsing

Use VTTScanner for VTT region settings parsing

Start transitioning the VTTRegion settings parsing code to use
VTTScanner, by modifying VTTRegion::parseSetting (the "name=value pair"-
part of the parsing) to use VTTScanner.

Remove VTTParser::collectWord since it becomes unused.

BUG=305317
Committed: https://src.chromium.org/viewvc/blink?view=rev&revision=165149

[jochen (gone - plz use gerrit), 2014-01-15 13:24:09]

i'm deferring to Mike

[Mike West, 2014-01-15 14:13:57]

On 2014/01/15 13:24:09, jochen wrote:
> i'm deferring to Mike

I'm deferring to... oh. Crap.

I'll look at this shortly. :)

[Mike West, 2014-01-15 14:27:20]

LGTM. Thanks for making this simpler.

[commit-bot: I haz the power, 2014-01-15 16:56:51]

CQ is trying da patch. Follow status at
https://chromium-status.appspot.com/cq/fs@opera.com/137033002/1

[commit-bot: I haz the power, 2014-01-15 17:20:35]

Change committed as 165149