Web updates

HTML a5113415d28e

Add more checks when matching SharedWorkerGlobalScopes This adds a check to see if the type and credentials values passed to the SharedWorker constructor match any previous instantiations of SharedWorkerGlobalScope with the same URL, before connecting the new SharedWorker to that SharedWorkerGlobalScope. If the check fails, we now fire an error event and do not connect to the SharedWorkerGlobalScope; previously, we would ignore any mismatches. Fixes #5235. Tests: