Enable WEBCONTENT_GPU_SANDBOX_EXTENSIONS_BLOCKING on macOS.
<rdar://problem/114834841>
Pull request: https://github.com/WebKit/WebKit/pull/20699
Committed 271179@main (126af484ebb4): <https://commits.webkit.org/271179@main> Reviewed commits have been landed. Closing PR #20699 and removing active labels.
Re-opened since this is blocked by bug 266112
Pull request: https://github.com/WebKit/WebKit/pull/24626
Committed 274941@main (37058f49d695): <https://commits.webkit.org/274941@main> Reviewed commits have been landed. Closing PR #24626 and removing active labels.