The merger of China's video giants Youku and Tudou this August must have struck a nerve over at Baidu: the search engine just bought out equity firm Providence's controlling stake in iQiyi, an already large video service built solely around streaming professional movies and TV shows. Should the deal wrap up as planned in the fall, Baidu plans to keep its new partner as a separate badge but weave its content throughout mobile sites and search results. The company is unsurprisingly taking a Google-like strategy to make sure it isn't left on the sidelines as searchers go elsewhere for vi