Intent to implement & ship: queueMicrotask

Summary: queueMicrotask exposes the platform primitive to queue microtasks. Without the API, web pages have used hacks around MutationObserver or Promise. Bug: https://bugzilla.mozilla.org/show_bug.cgi?id=1480236 Link to standard: https://html.spec.whatwg.org/multipage/timers-and-user-prompts.ht

Phabricator Maintenance May 25th

Phabricator will be undergoing maintenance tonight for approximately 10 hours (25 May 2019 04:00 to 14:00 UTC). During this maintenance: - The Phabricator web UI will function mostly normally. - Landed revisions will not auto close, but will do so when maintenance completes. - Backed-out revisions