MINNEAPOLIS — General Mills, Inc. is introducing a new variety of its Fiber One 90-Calorie Brownies: chocolate chip cookie. Made with semisweet chocolate chips in a cookie-batter brownie, the new item contains 5 grams of fiber per serving. The chocolate chip cookie variety will join the line’s two other flavors — chocolate fudge and chocolate peanut butter — in June at a suggested retail price of $3.89 for a 6-count box.