Well, no. But it depends on what you mean by 'chocolate'. If you want a chocolate flavor, you can 'dry chocolate' with cocoa nibs. But regular chocolate, the candy, has things like milk solids, oil, etc in it and that won't work. You can use brewing sugar, or another type of extract, if you'd like to replace the sugar in the beer.
I was looking to add some chocolate undertones but didn't want to go over the top with sugar. Chocolate nibs sound like the way to go or perhaps baking cocoa powder.