[webvtt] Pull Request: Update the rendering when line alignment/position alignment change

zcorpan has just submitted a new pull request for 
https://github.com/w3c/webvtt:

== Update the rendering when line alignment/position alignment change 
==
@alastor0325 can you review?

See https://github.com/w3c/webvtt/pull/309

Received on Friday, 1 July 2016 08:52:09 UTC