While musing about how chain restaurants of the non-fast food variety will deal with $22/hour wages in CA, I thought of one approach. Post a sign in the restaurant saying the state law now requires we pay our help a living wage. We suggest (or insist?) tipping is no longer necessary.
If they really want to make it stick, refuse to process credit card transactions for more than the amount on the tab. I wonder how diners will like the rude waitstaff when "being nice to get a tip" no longer works?