Sync web-platform-tests PR 24943 into mozilla-central (this bug is closed when the sync is complete).

PR: https://github.com/web-platform-tests/wpt/pull/24943
Details from upstream follow.

George Steel <gtsteel@google.com> wrote:

Move worklet-animation-local-time-null to WPT and add cases

Add case for setting localTime to null after having it set to a number.
Port to WPT infrastructure (testharness + reftest).

Bug: 870711
Change-Id: Iae22083f63004153666f4e119cf350f86c65eb55
Reviewed-on: https://chromium-review.googlesource.com/2348008
WPT-Export-Revision: 980c1fe551d9408daf590c8ff3cba0b877ff21e8

CI Results

Ran 0 Firefox configurations based on mozilla-central, and Firefox, Chrome, and Safari on GitHub CI

Total 2 tests

Status Summary

Firefox

OK : 1
FAIL : 4
TIMEOUT: 1

Chrome

OK : 1
PASS : 5

Safari

OK : 1
FAIL : 4
TIMEOUT: 1

Links

GitHub PR Head
GitHub PR Base

Details

New Tests That Don't Pass

/animation-worklet/worklet-animation-local-time-null-1.https.html
A worklet which never sets localTime has no effect.: FAIL (Chrome: PASS, Safari: FAIL)
A worklet which sets localTime to null has no effect.: FAIL (Chrome: PASS, Safari: FAIL)
A worklet which changes localTime to from a number to null has no effect on transform.: FAIL (Chrome: PASS, Safari: FAIL)
A worklet which changes localTime to from a number to null has no effect on backgroundColor.: FAIL (Chrome: PASS, Safari: FAIL)
/animation-worklet/worklet-animation-local-time-null-2.https.html: TIMEOUT (Chrome: PASS, Safari: TIMEOUT)

https://hg.mozilla.org/mozilla-central/rev/186e7f9a307c