Thursday afternoon, San José, California. Justin Bieber sits in a dressing room that's usually home to the San José Sharks hockey team. But there are 23 Sharks and only one of him – a tiny boy in a huge room, empty but for a sofa, a documentary-maker pointing a camera at me (Jon M Chu, director of Step Up 3D, now making Justin Bieber Never Say Never 3D), his press man Mike, and his Xbox. He has,