This isn't entirely right because Chrome OS is using a lot more of normal desktop Linux than Android does, which basically uses none.
https://en.wikipedia.org/wiki/ChromeOS
Android is this completely different thing (built round OpenBinder) that ended up using the Linux kernel for good hardware support. It's basically got nothing to do with desktop Linux, bar needed it to actually build Android. You can argue that Google basically tried forking Linux for Binder and control.