"Chocolate wasted" is most frequently used in context to me "very drunk", although that is not its origin.
The quote is originally from the movie Grown Ups, where Adam Sandler's character answers a table of kids wanting to know what being "wasted" means and he tells them it's a "hankering for ice cream". A little girl then yells out "I wanna get chocolate wasted!".
People now use it just to mean very drunk and they generally use the complete quote from the movie.
Bob: Let's hit up the bars tonight.
Sam: Yeah, I could use a few drinks after all this studying.
Kara: I wanna get chocolate wasted!!
Everyone: (laughs hysterically)