Latest Chrome OS 3XXX user agents:

User Agent Browser Device
Mozilla/5.0 (X11; CrOS x86_64 3912.23.0) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/27.0.1453.46 Safari/537.36 Chrome 27 Unknown
Mozilla/5.0 (X11; CrOS x86_64 3701.81.2) AppleWebKit/537.31 (KHTML, like Gecko) Chrome/26.0.1410.57 Safari/537.31 Chrome 26 Unknown
Mozilla/5.0 (X11; CrOS i686 3912.101.0) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/27.0.1453.116 Safari/537.36 IABrowser368a163e8e9 Chrome 27 Unknown
Mozilla/5.0 (X11; CrOS i686 3912.101.0) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/27.0.1453.116 Safari/537.36 IABrowser36841372f17 Chrome 27 Unknown
Mozilla/5.0 (X11; CrOS i686 3701.81.2) AppleWebKit/537.31 (KHTML, like Gecko) Chrome/26.0.1410.57 Safari/537.31 Chrome 26 Unknown
Mozilla/5.0 (X11; CrOS i686 3428.193.0) AppleWebKit/537.22 (KHTML, like Gecko) Chrome/25.0.1364.126 Safari/537.22 Chrome 25 Unknown
Mozilla/5.0 (X11; CrOS armv7l 3912.101.0) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/27.0.1453.116 Safari/537.36 Chrome 27 Unknown
Mozilla/5.0 (X11; CrOS armv7l 3428.193.0) AppleWebKit/537.22 (KHTML, like Gecko) Chrome/25.0.1364.126 Safari/537.22 Chrome 25 Unknown
Mozilla/5.0 (X11; CrOS i686 3912.101.0) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/27.0.1453.116 Safari/537.36 Chrome 27 Unknown