If it's chocolate on things, like a 3 Musketeer or a Milky Way or a Snickers, it's ****ing called a candy bar.
Saying "chocolate bar" implies that it is a bar of pure chocolate and nothing else. Exceptions can be made if it's something like a Hersheys bar with peanuts in it or something.
The idea that someone would call a Snickers a "chocolate bar" pisses me off, and it pisses me off when people call candy "sweets." Both of these represent an unacceptable lack of specificity within a dialect.