Good place to start would be looking into what the latest Toribsash linux versions are.
Latest Linux seems to be 3.5 and the latest Ubunt is 4.7. So as far as the game goes that's what you'll be working with.

I'm not all that knowledgeable about Linux packages and their portability let alone how chrome os ties into it but start with this and do some reading.

Also not sure how it works if you install steam os on linux/chrome and then install toribash? Probably good to let someone with more linux knowledge chip in.

Edit: As a last resort you could look into emulation/vm. As an aside it could be a cool project to somehow do a toribash docker image too.