NEW YORK — Starbucks is shutting down its struggling Teavana chain, and relying on customers who spend more on pricier drinks and food to drive up sales at its namesake coffee stores. The company reported disappointing sales growth on Thursday, and said it will close all 379 Teavana locations over the coming year. It had acquired the U.S. mall-based chain in 2012, with then-CEO Howard Schultz citing the potential for the tea market.