Yep I was wrong and heres how it is done
Basically, the plastic is etched to give it tooth, then it is "sensitized" with a palladium chloride, or tin chloride, or sequential application of both, which leaves receptor spots on the plastic. Then electroless nickel (actually autocatalytic nickel) begins depositing on the receptor sites, and upon it itself. Then the parts is plated with several layers of nickel, then chrome plate.