Use an ObjectIdentifier<> for DisplayLink observer IDs
Created attachment 399783 [details] Patch
Comment on attachment 399783 [details] Patch Nice! R=me.
Committed r261900: <https://trac.webkit.org/changeset/261900> All reviewed patches have been landed. Closing bug and clearing flags on attachment 399783 [details].
<rdar://problem/63425346>