Port more focus controller unit tests and fix our focus rules.

Now that we're seriously testing the focus controller stuff, the tests
are pointing out major problems in our focus rules implementation. This
brings our BasicFocusRules up to the aura version, which is needed for
the tests ported over.

BUG=431047
R=sky@chromium.org

Review URL: https://codereview.chromium.org/747163002