Comment 5 for bug 915382

This or something similar to this existed in Ubuntu 10.04 LTS, and the behavior was spot on.

In 10.04 at the login screen (not sure if it was lightdm back then), when the computer's power button was pressed, a popup was displayed. The popup propmted the user with shutdown options: shutdown, restart, cancel, ... . The popup also contained a 60 second countdown, that when exceeded shutdown the computer.

The countdown was benifical on two fronts. The first allowed the user to cancel the shutdown if the computer's power button had been inadverntaly pressed. The second allowed the user to shutdown the system without typing or mouse clicking. The latter is particullay useful if the computer is used primarliy as a server and occasionaly as a desktop.