Test is a flaky timeout according to history on macOS. The first occurrence of failure is at r265710
Test expectation while investigated:
Created attachment 407736 [details]
When `usesLTRUserInterfaceLayoutDirection` is set to , the `muteButton.iconName` should really be `Icons.VolumeRTL`. I'm not really sure how this ever worked :/
Committed r266475: <https://trac.webkit.org/changeset/266475>
All reviewed patches have been landed. Closing bug and clearing flags on attachment 407736 [details].