"Your app must adhere to the Metro style app model," that agreement states.

But Google's deviations won't keep Chrome from Metro because Microsoft has given browser makers -- and only them -- a free pass.

, including Google and Mozilla, access to the desktop's Win32 APIs (application programming interfaces) from within Metro on Windows 8.

The deal also lets browser vendors package the Metro versions with their desktop editions -- the former is more of a wrapper around Win32 code rather than a start-from-scratch Metro app -- which lets them sidestep the curated Windows Store, the sole distribution portal for Metro apps.

So while Microsoft's guidelines for Metro apps might bar Chrome from the store, Google doesn't have to follow those rules.