This bug whitelists a few more IOKit properties that I've seen in bug reports. These don't seem to create user-visible issues, but they are likely to cause the media stack (or other graphics code) to fail to use hardware feature on the system forcing a fallback to a less efficient code path.
Created attachment 334866 [details] Patch
Comment on attachment 334866 [details] Patch Clearing flags on attachment: 334866 Committed r229175: <https://trac.webkit.org/changeset/229175>
All reviewed patches have been landed. Closing bug.
<rdar://problem/38071245>
This is actually: <rdar://problem/37853282>