I control the portion of chips I eat by selecting the number of chips that fits in my nutrition plan then break them into smaller pieces. This is especially helpful with chips & salsa. This method of chip eating gives me the feeling of "grazing", but in a controlled way. I also don't feel so guilty when I log my meal afterwards.
To break up the chips, I put my chips on an appetizer sized plate (ask for one if needed), place a napkin over the chips and gently press down. The idea is not to pulverize the chips, just break them into smaller pieces that are still big enough to dip & pickup. Depending on the size of the chips, you can easily turn one chip into 3 or 4 chips instantly! I also try to eat the chips slowly so I don't finish before my meal comes. If I feel like I just have to have more, I only take 1 or 2 and break them up.