Actually the revocation is still under way though the Department of Labor announced that they had stopped enforcement in mid 2017.
In 2012 the DoL required that tips given to workers earning less than minimum wage are property of the worker. Until the, some restaurants had pooled all the tips, giving some to dishwashers and such (rather than paying them minimum wage) and even some to restaurant managers and owners, where that “some” for managers can even be the majority of tips paid.
California allows this under strict rules (involving the amount earned by the workers making tips, and very strictly who qualifies for a share). However at the federal level managers are once again free to keep some or all of tips. Supposedly “market forces” are adequate to restrain this. Note that the federal minimum wage for restaurant workers is different from the regular minimum wage: 2.13/hr rather than $7.30/hr — because they supposedly get tips!