SAN FRANCISCO – As investments go, Matt Cain is a U.S. Treasury Note. Slow and steady, if not too exciting. And remarkably reliable. So even when Cain had his early-season struggles along with others in the Giants rotation, you knew in the end you could take him to the bank. The right-hander appears to be turning a corner, and his timing was impeccable in an 8-2 victory over the Atlanta Braves Friday night.