[webvtt] Add default styling to "well-known" classes

zcorpan has just created a new issue for 
https://github.com/w3c/webvtt:

== Add default styling to "well-known" classes ==
See https://github.com/w3c/webvtt/pull/261#issuecomment-157855519

I think the default rendering should be the same in all user agents, 
but I don't really mind having a simple default stylesheet for webvtt 
with some classes like "red".

One problem is if we want to support changing the background color of 
the background box, we probably have to add a way to specify classes 
on cues.

This would actually be backwards compatible syntax if we need classes 
on cues:
```
WEBVTT

00:00:00.000 --> 00:00:10.000.foo.bar align:start
Hello world.
```

Please view or discuss this issue at 
https://github.com/w3c/webvtt/issues/270 using your GitHub account

Received on Wednesday, 18 November 2015 22:56:01 UTC