The following layout test is flaky on imported/w3c/web-platform-tests/html/dom/interfaces.worker.html Probable cause: This test was marked as a flaky failure when it was imported in https://bugs.webkit.org/show_bug.cgi?id=170713. It currently fails on every run. It is also a flaky timeout on macOS. Flakiness Dashboard: https://webkit-test-results.webkit.org/dashboards/flakiness_dashboard.html#showAllRuns=true&tests=imported%2Fw3c%2Fweb-platform-tests%2Fhtml%2Fdom%2Finterfaces.worker.html
Updated TestExpectations in https://trac.webkit.org/r231470