How do I shut down from the GUI? No gear is showing.

I did a minimal install, then installed ubuntu-desktop without recommends. I also installed policykit-desktop-privileges, but still no little gear (cog wheel) shows up in the top right-hand corner of the screen where I could click to get the shutdown and reboot options.

How do I get that little gear (cog wheel) in the top right corner back, which would give a menu with shutdown and reboot options?