The San Francisco Chamber of Commerce is “outraged” over a ballot measure to raise San Francisco’s minimum wage to $15 an hour, saying in a statement on Monday that it “flies in the face of collaboration and partnership.” The measure would lift base pay about 40 percent from its current $10.74, making San Francisco’s minimum wage the highest in the country. Activists were expected to file papers on Monday for the November ballot. The measure, designed by SEIU Local 1021, the Alliance of Californians for Community Empowerment, and other activist groups, would give companies with fewer than 100 employees until...