If the chips in question are denominated in Bitcoin itself, the problem of volatility is solved automatically (in fact, it doesn't even arise in the first place). That would mean your losses as well as winnings are still denominated in Bitcoin. So no matter how much Bitcoin's dollar price changes, the casino wouldn't be affected by this change. Indeed, their Bitcoin bankroll would have then to be in actual bitcoins (to pay out what's due), but isn't it exactly what online casinos keep their bankrolls in anyway?
In this case they would need to have two different kinds of chips: regular ones and some with a sign of
BTC on them so that a casino cashier knew what to give in exchange for those chips. It would work fine with slot machines, but think of a poker table. What if other players don't want those bitcoin chips? Theoretically, dealers could constantly make adjustments according to the current exchange rate, but imaging what a headache it would be for them
But let's admit it, this is a minor issue really
So you want to play poker but for some obscure and incomprehensible reason don't want to have anything to do with Bitcoin (even though "when money talks bullshit walks" and all such witticisms). But you play and you win, ending up with your pockets full of Bitcoin chips
And so what? The winner takes it all, right? So it is not a casino's headache, not in the least. Yep, you got it right - it is the loser who is to pay for the "adjustments according to the current exchange rate" (unless the winner changes his mind in the process, so to speak)!