I assume ChromeOS has a CLI terminal application. Does it open up in a browser tab, or is it an independent window? Does anyone have any screenshots handy?
I have a Chromebook Samsung Series 5. CTRL-ALT-T provides a "crosh" terminal but there is no shell available. SSH works in limited fashion, and ssh keys must be generated elsewhere and on attached media. "ssh" opens the ssh subsystem, and from there you use "key" to select the identity file. Then you use "host" to specify the system to connect to, and "connect" to ssh to it. You can also forward ports, but it will only allow binding of local ports 8000-8999 inclusive.
Update: Full tomfoolery possible in developer mode: http://www.chromium.org/chromium-os/developer-information-for-chrome-os-devices/samsung-series-5-chromebook
It seems most Chromebook devices will have this "not easily accessible" switch to turn on the full capabilities.