With Andrea working on other things I don't think this has an owner in DOM currently. Maybe Johann can help out? The impacted tests do not seem very interesting to us apart from storage access and clipboard APIs, but there are lots of permissions-gated things that are worth testing across browsers.
Bug 1524074 Comment 7 Edit History
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With Andrea working on other things I don't think this has an owner in DOM currently. Maybe Johann can help out? (I initially wrote something about the tests listed above, but I did not see that was a scrollable box. It seems our coverage for quite a few APIs could be improved by this.)