This is the damage calculation formula. Critical hits count under the "modifier" section.

Critical hits will have a value of 2 if they happen (or 3 if your pokemon has sniper) otherwise, they just have one.

I tried this out on PO by attacking a pair of Porygon 2 with frost breath: one with evolite, and one without. There is some error since there is a random digit coming into account, but there was a fairly significant difference in damage done, meaning the game still does take into account evolite and other items for that matter. There's also the fact that the game runs through stats before modifiers, so it would have accounted for the stats before the modifiers.