In Bug 179747 I removed access to the MediaAccessibility mach port, as well as read/write access to various preferences associated with that process, as it was no longer needed by modern WebKit media routines.
Detailed testing reveals that read access is still needed to these preferences to properly handle custom caption styles.
This patch re-enables access to the media accessibility preferences.
Created attachment 341217 [details]
Comment on attachment 341217 [details]
Clearing flags on attachment: 341217
Committed r232162: <https://trac.webkit.org/changeset/232162>
All reviewed patches have been landed. Closing bug.