Add a centerControlsBar in the media-controls element
Created attachment 451852 [details] [fast-cq] Patch
<rdar://problem/88884663>
<rdar://problem/88884670>
Committed r289751 (247227@main): <https://commits.webkit.org/247227@main> All reviewed patches have been landed. Closing bug and clearing flags on attachment 451852 [details].