Update region if it has changed after rendering footer (bug 1066774)

Follow-up to #663 
https://bugzilla.mozilla.org/show_bug.cgi?id=1066774

We do wait for the consumer info promise before triggering 'navigate', so the region in the views is OK, but the footer can be rendered before that.


Yes, from the debug page triggering `reload_chrome` is enough.

Everything I've modified is in fact inside the handler for `reload_chrome`. I could have moved the promise consumption outside of this function and make it trigger `reload_chrome`, which will re-render the footer and header, but this is wasteful, AFAIK only the region is problematic.