Brian Niccol's move affects both of these companies significantly.The restaurant industry was abuzz last week with the surprise announcement that star CEO Brian Niccol was leaving the burrito world for a taste of coffee. He steered Chipotle Mexican Grill (CMG 3.45%) out of a marketing disaster when he took the helm in 2018, and the stock gained more than 950% from the time he took over through to its stock split this June.Starbucks (SBUX -0.25%) investors are hoping that he can bring some fresh brew to thei ...