San Francisco police officers are being asked to combat racism in the ranks and take a pledge to turn in colleagues displaying intolerant behavior, such as slurs and jokes targeting people of color, gays and women. The pledge is part of a broader public relations campaign by the embattled police department to repair frayed relations with minority neighborhoods and community activists. The campaign comes amid growing tensions between police and black communities that are shaking up departments across the country and have led to the dismissal of top brass in some cities, including Chicago. Politically progressive San Francisco is not...