Enable H264 low latency code path by default for MacOS
<rdar://problem/66492801>
Created attachment 406377 [details] Patch
Comment on attachment 406377 [details] Patch r=me once the bots are happy
Committed r265547: <https://trac.webkit.org/changeset/265547> All reviewed patches have been landed. Closing bug and clearing flags on attachment 406377 [details].