In particular, make it possible to diagnose issues where the GPU process is failing to acknowledge graphics context flushes on behalf of the web process.
Created attachment 433480 [details] Patch
Tools/Scripts/svn-apply failed to apply attachment 433480 [details] to trunk. Please resolve the conflicts and upload a new patch.
Created attachment 433527 [details] Rebase on trunk
Committed r279926 (239673@main): <https://commits.webkit.org/239673@main> All reviewed patches have been landed. Closing bug and clearing flags on attachment 433527 [details].
<rdar://problem/80599150>