By Julien Pretot BAGNERES DE LUCHON, France (Reuters) - When Chris Froome took the yellow jersey with a brutal uphill attack in the 2015 Tour de France, he faced a barrage of doping insinuations but this year he seized control of the race in a descent and has been spared any controversy. Britain's Team Sky rider had humiliated his rivals with a stunning acceleration up to La Pierre Saint Martin last year, prompting a heated debate about his power data and the possible use of a hidden motor. Saturday's move in the final downhill section of the eighth stage, a 184-km ride from Pau, took his rivals by surprise, and probably Froome's critics as well. More...