RELEASE_ASSERT() hit in MediaControlTextTrackContainerElement::createTextTrackRepresentationImage()
<rdar://problem/54173656>
Created attachment 393160 [details] Patch
Created attachment 393163 [details] Patch for landing
Looks like this affects the behavior of some of the textTrack tests; we no longer synchronously change style within the script; that is the intended behavior, but we should update the tests to take this into account.
*** This bug has been marked as a duplicate of bug 208904 ***