Comment 13 for bug 1624407

Generally speaking fixing bug 1674749 (now bug 1671424) should be enough for most apps in the short term.

I'm reminded of how Microsoft handles this problem...

WM_CLOSE: https://msdn.microsoft.com/en-us/library/windows/desktop/ms632617(v=vs.85).aspx

WM_QUIT: https://msdn.microsoft.com/en-us/library/windows/desktop/ms632641(v=vs.85).aspx
"The WM_QUIT message is not associated with a window and therefore will never be received through a window's window procedure."

WM_POWERBROADCAST: https://msdn.microsoft.com/en-us/library/windows/desktop/aa373247(v=vs.85).aspx

WM_ENDSESSION: https://msdn.microsoft.com/en-us/library/windows/desktop/aa376889(v=vs.85).aspx

Each has a valid use case, and I don't think we can get away from similarly wanting a 'quit' message in Mir eventually.