permissions.query() tests

[annevk]

For #138 we should have permissions.query() tests. We agreed this could be a follow-up.

[johannhof]

Tests landed in Chromium in https://chromium.googlesource.com/chromium/src/+/4d0a919a0687e67853f470ea4dfe93fc4aaaf81d and should be getting synced soon.