[ttml2] Pull Request: Define significant text node, text node, and element node (#1105).

skynavga has just submitted a new pull request for https://github.com/w3c/ttml2:

== Define significant text node, text node, and element node (#1105). ==
Closes #1105.

See https://github.com/w3c/ttml2/pull/1107

Received on Friday, 31 May 2019 07:02:04 UTC