Doesn't work on Edge, Firefox, or even Safari. I am sorry, your first sentence "big believers in standards" is just a lie. It is just developer laziness for supporting non standard stuff and doing User Agent sniffing.
Rule #1 is do feature detection not user agent detection. What are you doing that is "pretty deep in the browser"? NaCL? Experimental Chrome features?
Rule #1 is do feature detection not user agent detection. What are you doing that is "pretty deep in the browser"? NaCL? Experimental Chrome features?