Modified bridge to used slots for keeping the values previously kept in cookies. These slots are backed by either cookies are the local storage. The local storage implementation is preferred if the browser provides the feature.
Please add instructions for QA on how best to test both cookieful and cookie less modes for push also.
To disable local storage follow the instructions described here: http://webdevwonders.com/clear-dom-storage/
Testing should be focused on verifying if notifications are received, first using one window and then with multiple windows/tabs.
Back-ported changes to maintenance branch.