Shadow DOM

2016-06-01: Léonie and Dylan Barrow are tracking. ACTION-2052 Cynthia to review later this summer.
2016-10-19: Reassign action to Shane.
2017-01-18: Shane to coordinate with Rich.
at some point: reassigned action to Becky.
2018-01-17: Charles asserts Shadow DOM will be incorporated into DOM.
2018-03-01: Published as retired.
2018-03-14: Invite Charles Nevile to APA to update us on status.
2018-05-23: On active review, decided to close this because it's been retired.