Sync web-platform-tests PR 38929 into mozilla-central (this bug is closed when the sync is complete).

PR: https://github.com/web-platform-tests/wpt/pull/38929
Details from upstream follow.

Henrik Boström <hbos@chromium.org> wrote:

De-flake RTCRtpReceiver-getStats.https.html.

The callee's candidate pair may not be formed until connected, but the
test is waiting for the caller to be connected, not the callee. There
may be a race here where caller's pair is formed just before the calle's
pair. Probably the callee was still checking.

Bug: chromium:1422777
Change-Id: Ia04c3d74b20d4bd6d44eb5b57f551202f3dc91e1
Reviewed-on: https://chromium-review.googlesource.com/4328130
WPT-Export-Revision: c1569702006cdcaa029691890d94ebb71e4a5228

CI Results

Ran 9 Firefox configurations based on mozilla-central, and Firefox, Chrome, and Safari on GitHub CI

Total 1 tests and 5 subtests

Status Summary

Firefox

OK : 1
PASS: 1
FAIL: 4

Chrome

OK : 1
PASS: 1
FAIL: 4

Safari

OK : 1
PASS: 1
FAIL: 4

Links

Gecko CI (Treeherder)
GitHub PR Head
GitHub PR Base

Details

New Tests That Don't Pass

• /webrtc/RTCRtpReceiver-getStats.https.html [wpt.fyi]
  • receiver.getStats() via addTransceiver should return stats report containing inbound-rtp stats: FAIL (Chrome: FAIL, Safari: FAIL)
  • receiver.getStats() via addTrack should return stats report containing inbound-rtp stats: FAIL (Chrome: FAIL, Safari: FAIL)
  • receiver.getStats() should work on a stopped transceiver: FAIL (Chrome: FAIL, Safari: FAIL)
  • receiver.getStats() should work with a closed PeerConnection: FAIL (Chrome: FAIL, Safari: FAIL)

https://hg.mozilla.org/mozilla-central/rev/a9600573e20b