So, wait, what? Why again?
Chrome OS, minus all of the things that would give you any reason to run it or any kind of support, plus a bunch of hassles and problems. Sounds like fun?
Or if that is not your party, just load chrome (the browser) on top of a geriatric hardware friendly Unix and get a real functioning OS and the one thing that probably works in Flex. Or send the old warhorse off to pasture and just grab one of the million Chromebooks on their way to the landfill.
Still, this project may yet get past the academic exercise phase who knows? And I am really in no position to throw stones, I once helped a fried hack together an OS on an old WinChip embedded system. We and an industry have some strange hobbies, when we aren't playing dwarf fortress.