But as long as Google and now Sundar Pichai consider ChromeOS to be the one and only Google desktop OS ever, unfortunately that won't happen. Of course such a desktop OS would also have to be more like Android Wear than "AOSP" - as in only Google would ever control the interface and only Google would be in charge of updates.
I suspect Google actually wants Android to be more like Chrome OS. But they know Android's too important and popular to risk by outright replacing it with Chrome OS. That's why they are slowing mixing them together.
Chrome on Android is now integrated in the taskbar while they are pushing things like Web Manifests, Web Workers and Web Push Notifications. On the other hand it is now possible to run Android apps on Chrome OS via App Runtime for Chrome (ARC).
http://www.jide.com/en/remixos
But as long as Google and now Sundar Pichai consider ChromeOS to be the one and only Google desktop OS ever, unfortunately that won't happen. Of course such a desktop OS would also have to be more like Android Wear than "AOSP" - as in only Google would ever control the interface and only Google would be in charge of updates.