This was an unexpected move from Google. I am guessing they are trying to have singleton system around their app market but this is not how it is supposed to be done. They can give users a unique email address with play store domain and ask them to sign in if they want to give a different user experience to Google users. And you need to have installed Google OS or Chrome in order to get that email address. With this…
> This is not the first time Google is doing this
Really, this should be no surprise precisely because it's far from the first time; numerous Google properties use UA-sniffing (many in combination with whitelists, which is nothing but badness for the open web, where any standards compliant browser should be fine!). An increasing number are supporting Chrome only at initial launch, which really is sad.
The fact that Opera, who nowadays build on top of the Chromium Content API, have a comment in browser.js after dodging the UA-sniffing saying the following says a lot:
> Google, please make sure your obfuscator does not change class names, so our patch continues working (or stop browser-sniffing as we both use and contribute to Blink!) - love, Opera.
(from https://github.com/operasoftware/browserjs/blob/ceef10b34f63...)