Bug 1089528 - Do not open app until utility tray is pulled down

https://bugzilla.mozilla.org/show_bug.cgi?id=1089528
For reference, that was this platform bug: https://bugzilla.mozilla.org/show_bug.cgi?id=625289 which has since been fixed. We should try to avoid adding these timeouts unless they're necessary (and if they are, we should document why), it's extra overhead and probably confusing for someone new to the code.