Layout test compositing/filters/opacity-change-on-filtered-paints-into-ancestor.html is a flaky image failure on Mojave WK1. The image diff shows that one of the blue squares is not as blurred as expected.
Created attachment 350132 [details] expected image
Created attachment 350133 [details] actual image
I have not yet confirmed, but this may have regressed with https://trac.webkit.org/changeset/235630/webkit
<rdar://problem/44607384>
The test became flaky on GTK around that revision: https://webkit-test-results.webkit.org/dashboards/flakiness_dashboard.html#showAllRuns=true&tests=compositing%2Ffilters%2Fopacity-change-on-filtered-paints-into-ancestor.html
Marked test as flaky in https://trac.webkit.org/r236921