I am trying to test android app on Chrome OS running in VirtualBox based on these instructions on android developers site.
One of steps is to enable Developer mode on Chrome OS. Instructions for some devices can be found here but I am not sure how to enable it on Chrome OS in VM.
Chrome OS image is downloaded from this link
Can anybody help? Is it even possible?
The link you've provided is not a ChromeOS image (ChromeOS is only available pre-installed on hardware from Google manufacturing partners, eg. Chromebooks), but ChromiumOS-based distribution, provided by the third-party vendor.
At the moment (Q4'2017), it is possible to run Android Apps only on ChromeOS (not ChromiumOS), and only on the specific hardware.
