Steps to reproduce: 1. Go to http://chat.meatspac.es/ 2. While the camera permissions dialogue is up, close the tab. Now if you could to about:memory, click "minimize memory usage", then "measure", you'll see this: 20.16 MB (05.08%) -- top(none)/ghost/window(https://chat.meatspac.es/) (it may not say ghost window immediately, but it will still be there) This is bad because we're leaking 20mb forever (it was hanging around for quite a while), and because it is a leak, the CC gets really slow (55ms vs more like 5ms otherwise). I'm not sure if it is required to close the tab before the permissions dialogue is gone or not, but my guess would be it is somehow related to that, because we've seen similar things before.