[ServiceWorker] about:blank handling in openWindow doesn't make much sense (#696)

The about:blank handling in openWindow as it is written right now has the following properties:

1. If *url* is `about:blank`, the returned promise is resolved with `null`.
2. The newly created browsing context's document has an origin that is an opaque identifier.

So there is no way for anyone other than the user can interact with the resulting browsing context.  Is this actually the desired behavior, and if so what's the point?

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Reply to this email directly or view it on GitHub:
https://github.com/slightlyoff/ServiceWorker/issues/696