(The "Canary" builds of Chrome are outside the normal beta channel and based on untested nightly Chromium builds.)
Current versions of Chrome can be made fullscreen, but don't show as proper fullscreen apps in Mission Control and overtake the desktop. The Canary build is compliant with Lion's implementation, including a fullscreen button in the upper right corner and an accompanying keyboard shortcut. Employing the fullscreen mode puts the Canary build into its own Space which is accessible via two-finger swipe or the two-finger tap gesture which brings up Mission Control.
UserAgent: Mozilla/5.0 (Macintosh; U; Intel Mac OS X 10.6; en-US; rv:22.214.171.124) Gecko/20110707 AlexaToolbar/alxf-2.13 Firefox/3.6.19