LayoutTest http/tests/xmlhttprequest/simple-cross-origin-progress-events.html is a flaky timeout https://build.webkit.org/results/Apple%20Sierra%20Release%20WK2%20(Tests)/r212119%20(3479)/results.html https://webkit-test-results.webkit.org/dashboards/flakiness_dashboard.html#showAllRuns=true&tests=http%2Ftests%2Fxmlhttprequest%2Fsimple-cross-origin-progress-events.html
This does not appear to be a recent regression