The following layout test is failing on Mac WK1 webanimations/accelerated-transition-interrupted-on-composited-element.html Probable cause: This test was added in https://trac.webkit.org/changeset/235843/webkit and has been having flakey image failure and now is constantly timing out Flakiness Dashboard: https://webkit-test-results.webkit.org/dashboards/flakiness_dashboard.html#showAllRuns=true&tests=webanimations%2Faccelerated-transition-interrupted-on-composited-element.html
This looks like more fallout from https://trac.webkit.org/changeset/235948/webkit
after testing this issue seems to be resolved as of: https://trac.webkit.org/changeset/235991/webkit closing bug
<rdar://problem/44473745>