It was used by Chromium port. Bug 45939 – Add entry points to GraphicsContext3D needed for Chromium compositor port
Created attachment 418706 [details] Patch
Created attachment 418708 [details] Patch
Created attachment 418709 [details] Patch
Created attachment 418753 [details] Patch
Comment on attachment 418753 [details] Patch r+ once the style issues are addressed and the EWS is happy.
Created attachment 418764 [details] Patch for landing
Committed r272075: <https://trac.webkit.org/changeset/272075>
<rdar://problem/73769262>