[Merge] lp:~artmello/webbrowser-app/webbrowser-app-fix_1484562 into lp:webbrowser-app

[Olivier Tilloy]

Not strictly necessary for tests to pass, but it would be better for the sake of completeness to re-implement the cleanup() method and have it clear historyMockModel.
-- 
https://code.launchpad.net/~artmello/webbrowser-app/webbrowser-app-fix_1484562/+merge/268165
Your team Ubuntu Phablet Team is subscribed to branch lp:webbrowser-app.