Code review comment for lp:~rharding/juju-gui/qa-ant-onboarding

QA not ok, but if you apply the following patch and write associated
tests, it will be good.

http://paste.ubuntu.com/6247161/

This makes the flag handling much less fragile
(http://localhost:8888/sidebar/:flags:/charmworldv3/onboard/ shows
onboarding as it should, for instance) and disables onboarding for the
fullscreen view, where it will be broken. Please merge this and then
write a few associated tests.

Thank you!

https://codereview.appspot.com/14700043/