Turns out I was wrong about WebKitApplyingScripts blocking these tests. We should kill WebKitApplyingScripts, but it's not as urgent as I though.
Created attachment 43958 [details]
Created attachment 43959 [details]
Comment on attachment 43959 [details]
You could make default_options take **kwargs and pass the overrides that way.
Committed r51443: <http://trac.webkit.org/changeset/51443>