chroming a metal is a chemical process. you dip the metal in a chemical bath and electrically charge it will attract the chrome plating. it's plating, just like any other kind of electroplating process. watch how it's made: http://www.youtube.com/watch?v=RJ6j6YjJrHY

you can't paint it true chrome, and all the "chrome" paints always run and look really awful.

take it to a powdercoating shop and ask them if they do chrome finishes or if they know anyone who does. it's expensive but not prohibitively so.