The Journeys Backyard BBQ Tour rolled into Roseville Saturday to amaze hundreds of action sports fans for its only California stop during the 2010 tour.   Fans from all over Northern California flooded the south parking lot of the Galleria Mall in Roseville for the opportunity to watch their favorite extreme sports athletes. The event brought Sacramento a rare opportunity to watch stars participate in freestyle motocross, skateboarding and BMX demos on a 60,000-square-foot playground of ramps.   The event featured stars Rob Dyrdek, Danny Way, Dave Mirra and riders from the Metal Mulisha freestyle motocross team.   While the athletes were not putting on a show, live bands entertained