When investigating time out for webgl/1.0.3/conformance/state/gl-object-get-calls.html, the test went from ~300ms to ~4000ms on my local machine.
Look for low-hanging improvements with synthetic GL errors and GPUP IPC.
<rdar://problem/92704244>
This was largely fixed with bug 253509 run-webkit-tests --release webgl/1.0.x/conformance/state/gl-object-get-calls.html --details --repeat 10 says first one takes 1.5s and next ones 0.01s *** This bug has been marked as a duplicate of bug 253509 ***