This page contains instructions on how to build your Unity application for Chrome OS. Chrome OS supports the Google Play Store and Android applications which means, to build an application for Chrome OS, Unity actually builds an Android application.
To configure your application to support Chrome OS devices:
After you configure your project to build for Chrome OS, you can start the build process. The build process for Chrome OS is the same as the one for Android. The only difference is if you want to use the Build and Run option to immediately run the build on a Chrome OS device. On Chrome OS, you must use Android Debug Bridge to connect to the target device. For information on how to do this, refer to Android Debug Bridge for Chrome OS devices. To build your application for Chrome OS, follow the instructions for Building Apps for Android.