“Snow White and the Huntsman” slew the domestic B.O. Friday with $20.3 million.This should come as a pleasant surprise to Universal, which pegged the film for an admittedly conservative $30 million weekend as damage control in the wake of their sunken “Battleship” just two weeks ago. The fairy tale now aims for at least a $55 million frame, a healthy start for a pic budgeted at upwards of $170 million. Sony’s “Men in Black 3″ took $8.3 million Friday, on course for a three-day take just south of $30 million. Pic, which dethroned “The Avengers” but still constitutes a slight disappointment for the studio, has cumed $91.3 million Stateside thus far. In third, Disney’s “The Avengers” grossed $5.7 million Friday for a cume of $538.1 million. This officially makes “Avengers” the third highest grossing film in U.S. history behind “Titanic” ($658.6 million) and “Avatar” ($760.5 million). And underperforming in its soph sesh, Warner Bros.’ “Chernobyl Diaries” dropped 71% to a gross of $1 million Friday for ninth place. Though the fall is steep, the scarer has cumed $12.4 million to date, barely shy of its $13 million budget before P&A.