By Ronald Grover LOS ANGELES (Reuters) – The Walt Disney Co has agreed to buy Maker Studios for $500 million, becoming a major online video distributor through the purchase of one of YouTubes largest networks, according to a person familiar with the deal. The deal, which grants the media and entertainment company a strong foothold in online video content and technology, is expected to be announced shortly. The company is partners with PewDiePie, the online persona of 24 year-old video gamer Felix Kjellberg, who with over 25 million subscribers is YouTubes single most-subscribed star.