Gap has fired its star design chief, Patrick Robinson, after seeing a decline in sales for every year he was at the helm of the company. No successor has been named. Robinson, a darling of fashion insiders, had previously designed for Paco Rabanne, Perry Ellis, Giorgio Armani, and Anne Klein and had been nominated for a Council of Fashion Designers of America award. As the public face of the Gap, he was covered like a celebrity for fashion blogs. But he joined the Gap in 2007, when the company was struggling to find its footing and had seen massive sales declines in the early part of the decade. Gap Inc.’s other units, including Banana Republic and Old Navy’s North American stores, posted positive same-store sales in 2010, but the Gap unit reported a 1 percent drop.