I am anti feeding fruit in any quantity to chams. Their guts are designed to cope with primarily insectivorious diets with some species eating some, marginal quantities of foliage, not the high sugar content of fruit. I personally don't think it is very good for the animal and don't see the use subjecting their gut to such high sugar rich material in their diet. Certain species are known to eat some berries in the wild during the dry season but this is likely for hydration purposes and this shouldn't be an issue in captivity. Just my 2 cents...
Chris