I notice on Ubuntu auto-update doesn't work. I wonder if this is a technological issue (they can't or haven't bothered to get it working) or a cultural one (like if Ubuntu programs shouldn't auto-update ever).
On Linux, the chrome team chose to integrate with system package managers instead of using their native updater - arguably the native updater would have worked better (many Linux distros still don't support delta updates!), but they wanted to buy goodwill with the Linux community.
I don't see any such thing on their download page, only for stable and beta. I think linux users are better equipped than most to build it from source, however...
When you install Chrome/Chromium in Ubuntu it adds a repository for the channel (stable, beta, dev, canary) that you chose. When you update Ubuntu, via the Update Manager or the terminal, it will fetch the latest version of Chrome and install it.
It does not make sense for an application to autoupdate itself when there's a system wide package management with updates available. There are also other reasons that are more cultural than technical in nature.
If you want bleeding edge versions of Chromium (or some other popular program), there are non-standard/third party repositories available. Then you can get nightly builds but still update your system with the package manager.
My guess is that Chrome/Chromium is installed system-wide from a distribution package, and when you run it as a normal user you don't have write permission for updating it.
