We register inner-window-destroyed" twice. Once in initHelper and right after in init again.
The try run showed some intermittent failures that didn't look intermittent any more. I pushed again https://tbpl.mozilla.org/?tree=Try&rev=0c8fc3c406b4
Created attachment 631012 [details] [diff] [review] patch The _id removal caused timeouts in the webapps tests.
ahhh so we can't remove the outerWindowID: http://mxr.mozilla.org/mozilla-central/source/browser/modules/webappsUI.jsm#92
https://hg.mozilla.org/mozilla-central/rev/9ed07c7da57b (Merged by Ed Morley)