[webvtt] Pull Request: Allow empty identifier for regions in the data model

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

== Allow empty identifier for regions in the data model ==
Fixes #353.

See https://github.com/w3c/webvtt/pull/354

Received on Tuesday, 15 August 2017 09:40:30 UTC