This is a testharness.js-based test.
PASS Calling OffscreenCanvas.commit() on main without transferControlToOffscreen rejects promise with an exception. 
PASS Calling WebGL's commit() on main without transferControlToOffscreen rejects promise with an exception. 
FAIL Calling WebGL's commit() on main without an OffscreenCanvas rejects promise with an exception. Cannot read property 'clearColor' of null
PASS Calling OffscreenCanvas.commit() on worker without transferControlToOffscreen rejects promise with an exception. 
Harness: the test ran to completion.

