What is the "shell" window type in chrome extensions? Can it be used to hide a window?

Question

I just noticed this in the trunk/dev channel:

type ( enumerated string ["normal", "popup", "panel", "app", "shell"] )

The type of browser window this is.

I tried it with with Canary: no window is shown, but we have console output, so something has been created. The thing is I just don't get it. How is this different from a background page?

I was hoping to toggle windows completely out of the user's view, without having to reload the window's content when toggling up. Anyway, I'm not hoping much as you can't update a window type with chrome.windows.update. But the question still remains: what is this "shell" type?

Answer 1

"shell" moved to the new chrome.app.window API in r140947. Then it appears to have disappeared from there in the dev documentation.

Answer 2

"shell" currently does nothing for extensions and should not be used.