heat chicken breast in a pan with no oil - ok for the pan?
Doing this will not harm the pan, assuming you do not heat the pan to absurd temperatures (which is no different than if you used oil).

It may not give you ideal results for your chicken, though.  Oil in the pan serves a couple of purposes.  In traditional (as opposed to non-stick) pans, of course it helps prevent sticking.  

It also provides a thermal coupling between the surface of the pan and the surface of the food, conducting heat from the one to the other (much akin to the way thermal paste helps your processor cooler work better).

Without this effect, you may get spottier and less reliable or uniform cooking of the chicken.