Del Monte Foods is moving its headquarters from San Francisco to Walnut Creek, a shift that will put the East Bay city's name -- albeit in small print -- on grocery store shelves across the country. Based primarily in San Francisco since the company's founding in 1886, Del Monte is transferring about 90 employees who work in marketing, finance and supply chain functions to 3003 Oak Road, an office building near the Pleasant Hill/Contra Costa Centre BART station.