I was about to type pretty much what ddiesel has but he beat me to it!

The lifter rides on the side of the lobe(which is why the lifter spins).

The chip is in the worse possible (well close to it) location. The other issue is that the highest stress on the lifter/lobe is as you get toward max lift, and that's near where the chip is.

Personally, considering you can get a new cam for a few hundred, I wouldn't risk it. You also have to ask why/how it chipped, is the rest of the lobe ready to disintegrate? (probably not but you never know)

If you could find out who ground the cam, they might be willing to rebuild and re-grind that one lobe for a fair bit less than a replacement cam, couldn't hurt to try and find out?