media/audio-controls-rendering.html, media/controls-strict.html, media/controls-without-preload.html failing on El Capitan

[Ryan Haddad]

Since they were rebaselined in <http://trac.webkit.org/changeset/198912>, these tests have been flaky and failing on El Capitan WK2

media/audio-controls-rendering.html
media/controls-strict.html
media/controls-without-preload.html

<https://build.webkit.org/results/Apple%20El%20Capitan%20Debug%20WK2%20(Tests)/r198943%20(4130)/results.html>
<http://webkit-test-results.webkit.org/dashboards/flakiness_dashboard.html#showAllRuns=true&tests=media%2Faudio-controls-rendering.html>
<http://webkit-test-results.webkit.org/dashboards/flakiness_dashboard.html#showAllRuns=true&tests=media%2Fcontrols-strict.html>
<http://webkit-test-results.webkit.org/dashboards/flakiness_dashboard.html#showAllRuns=true&tests=media%2Fcontrols-without-preload.html>

[Ryan Haddad]

Marked tests as flaky in <http://trac.webkit.org/changeset/198946>

[Alexey Proskuryakov]

Happens on macOS Sierra too.