media/track/track-cue-css.html is having image failure often in the bots. Probable reason: problems with color handling. I've seen this issue occur randomly in other media tests. https://build.webkit.org/results/GTK%20Linux%2064-bit%20Release%20(Tests)/r244109%20(10214)/media/track/track-cue-css-diffs.html
Moving to https://bugs.webkit.org/show_bug.cgi?id=198830 as there's a crash that's affecting several tests.