[webvtt] Pull Request: mark at-risk features in a new snapshot

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

== mark at-risk features in a new snapshot ==
Made a new snapshot for 2019-03-06 and manually applied 2c06667 and c9100e0.
Then I marked collision avoidance with snap-to-lines false, `::cue-region` and `::cue-region()` pseudo-elements, and `:past` and `:future` pseudo-classes as at-risk.
STYLE block is no longer marked at risk because I have a [prototype](https://github.com/videojs/vtt.js/pull/35) that would be completed during the mandatory 28-day waiting period after this snapshot is published as the new CR.

See https://github.com/w3c/webvtt/pull/449

Received on Wednesday, 6 March 2019 16:08:39 UTC