Created attachment 441459 [details] [diff] [review] patch From parent bug: Right now RestoreDocument_proxy is added as a listener for the load event, so that it can refill form data. However it's added directly, as opposed to every other event listener adding SS and then calling a method. So the context is weird when looking at the code. `this` is not SessionStore, it's the browser object. This has worked fine, but in doing probing work for bug 550967, I needed access to the SessionStore `this`, but couldn't get it without creating a global or attaching it to the tab, which is hacky.