Filed by: smolnar [at] mozilla.com
Parsed log: https://treeherder.mozilla.org/logviewer?job_id=378245478&repo=autoland
Full log: https://firefox-ci-tc.services.mozilla.com/api/queue/v1/task/cO495xyxRi6w6pF4a1WArA/runs/0/artifacts/public/logs/live_backing.log
Reftest URL: https://hg.mozilla.org/mozilla-central/raw-file/tip/layout/tools/reftest/reftest-analyzer.xhtml#logurl=https://firefox-ci-tc.services.mozilla.com/api/queue/v1/task/cO495xyxRi6w6pF4a1WArA/runs/0/artifacts/public/logs/live_backing.log&only_show_unexpected=1

 INFO - TEST-START | /screen-capture/getdisplaymedia.https.html
[task 2022-05-16T18:34:25.820Z] 18:34:25     INFO - Run 1/10
[task 2022-05-16T18:34:25.821Z] 18:34:25     INFO - Closing window e8b80081-4ae3-4285-9a20-10e44aa98c3d
[task 2022-05-16T18:34:39.794Z] 18:34:39     INFO - 
[task 2022-05-16T18:34:39.795Z] 18:34:39     INFO - TEST-PASS | /screen-capture/getdisplaymedia.https.html | getDisplayMedia in navigator.mediaDevices 
[task 2022-05-16T18:34:39.795Z] 18:34:39     INFO - TEST-PASS | /screen-capture/getdisplaymedia.https.html | getDisplayMedia() must require user activation 
[task 2022-05-16T18:34:39.795Z] 18:34:39     INFO - TEST-UNEXPECTED-FAIL | /screen-capture/getdisplaymedia.https.html | getDisplayMedia() must adhere to frameRate if set - assert_greater_than_equal: expected a number greater than or equal to 3.75 but got 3.701019287109375
[task 2022-05-16T18:34:39.796Z] 18:34:39     INFO - @https://web-platform.test:8443/screen-capture/getdisplaymedia.https.html:54:28
[task 2022-05-16T18:34:39.832Z] 18:34:39     INFO - ......................................
[task 2022-05-16T18:34:39.832Z] 18:34:39     INFO - TEST-OK | /screen-capture/getdisplaymedia.https.html | took 13992ms
[task 2022-05-16T18:34:39.836Z] 18:34:39     INFO - PID 1279 | 1652726079810	Marionette	INFO	Stopped listening on port 35456
[task 2022-05-16T18:34:40.377Z] 18:34:40     INFO - Browser exited with return code 0
[task 2022-05-16T18:34:40.381Z] 18:34:40     INFO - Closing logging queue
[task 2022-05-16T18:34:40.381Z] 18:34:40     INFO - queue closed
[task 2022-05-16T18:34:40.403Z] 18:34:40     INFO - Application command: /builds/worker/workspace/build/application/firefox/firefox --marionette about:blank -profile /tmp/tmpdup_0v2f
[task 2022-05-16T18:34:40.409Z] 18:34:40     INFO - Starting runner
[task 2022-05-16T18:34:41.100Z] 18:34:41     INFO - PID 1801 | 1652726081099	Marionette	INFO	Marionette enabled
[task 2022-05-16T18:34:41.103Z] 18:34:41     INFO - PID 1801 | 1652726081102	Marionette	INFO	Listening on port 55158
[task 2022-05-16T18:34:45.232Z] 18:34:45     INFO - PID 1801 | console.warn: SearchSettings: "get: No settings file exists, new profile?" (new NotFoundError("Could not open the file at /tmp/tmpdup_0v2f/search.json.mozlz4", (void 0)))
[task 2022-05-16T18:34:46.139Z] 18:34:46     INFO - TEST-START | /screen-capture/getdisplaymedia.https.html

:ng, since you are the author of the regressor, bug 1760843, could you take a look?
For more information, please visit auto_nag documentation.

It looks like it has already been backed out. I'll take a look.

Fixed by backout: https://hg.mozilla.org/integration/autoland/rev/9d4ff58359c27c213153f1cc9e9d523212d0d888