The following layout test is flaky on macOS WK1 webanimations/accelerated-transition-interrupted-on-composited-element.html Probable cause: The first failure was seen shortly after it was added in https://trac.webkit.org/changeset/235843/webkit, so it may be flaky from the start. Flakiness Dashboard: https://webkit-test-results.webkit.org/dashboards/flakiness_dashboard.html#showAllRuns=true&tests=webanimations%2Faccelerated-transition-interrupted-on-composited-element.html Link to failure with image diff showing a black square appearing closer to the left than expected: https://build.webkit.org/results/Apple%20Sierra%20Debug%20WK1%20(Tests)/r235845%20(9470)/results.html
<rdar://problem/44621674>
I can remove the flakiness with using a double rAF to conclude it. Additionally, we can improve the test by using a "transitioncancel" event.
Created attachment 366717 [details] Patch
Comment on attachment 366717 [details] Patch Clearing flags on attachment: 366717 Committed r243878: <https://trac.webkit.org/changeset/243878>
All reviewed patches have been landed. Closing bug.