Over in #11806 I'm removing the need for our offlinePass. And we've also removed the w/o javascript gatherer.

So in #11806 (comment) @brendankenny proposed we drop down to just 1 pass:

should service-worker move to redirectPass and only have two passes? service-worker would fail if the site doesn't redirect, but should http-redirect move to use driver.fetcher anyways?

and actually, with the new DevTools offline check, which is doing a real request, that means the ServiceWorker has to be activated and controlling the page. Presumably that means getServiceWorkerVersions/getServiceWorkerRegistrations will return the info, so do we even need a second pass anymore?

We'd move the 'service-worker' and 'http-redirect' gatherers to defaultPass and then we're good.

Patrick asked "can you request an insecure iframe on a secure page? I assume that would be blocked by mixed content" and noted: "no reason the offline pass needs to exist though"