REGRESSION: Three tests in media/track/track* fail together flakily

• Component: Tools / Tests
• Status: RESOLVED CONFIGURATION CHANGED

[Shawn Roberts]

The following layout test is flaky on Mojave WK1 Release and Debug

media/track/track-css-visible-stroke.html
media/track/track-cue-left-align.html
media/track/track-cue-line-position.html

Probable cause:

Unsure of point of regression. The 3 tests above fail in tandem on both queues. I have tried reproducing it by testing each test locally, and using the test runners from those runs and I cannot get them to fail. 

Looking at the stdio log, media/track/track-css-visible-stroke.html fails first with a reference mismatch, then the other two fail with failed unexpectedly (reference mismatch didn't happen)

Flakiness Dashboard:

https://webkit-test-results.webkit.org/dashboards/flakiness_dashboard.html#showAllRuns=true&tests=media%2Ftrack%2Ftrack-css-visible-stroke.html%20media%2Ftrack%2Ftrack-cue-left-align.html%20media%2Ftrack%2Ftrack-cue-line-position.html

Diff for media/track/track-css-visible-stroke.html:

https://build.webkit.org/results/Apple%20Mojave%20Release%20WK1%20(Tests)/r243707%20(4088)/media/track/track-css-visible-stroke-diff.png

[Radar WebKit Bug Importer]

<rdar://problem/49501367>

[Per Arne Vollan]

These tests do not appear to be flaky on Mac anymore.