Chrome OS Commit Suggest Android App Sideloading in the Works
A commit that was discovered by the Chrome Story team suggest that Chrome OS could have the ability for administrators to sideload Android apps on devices. Currently the only way you can sideload an APK to a Chromebook is if the device is in Developer Mode. That mode essentially bypasses all of the Google security measures like boot loader verification.
If this Commit makes it through the gauntlet and arrives on Chrome OS, there would be a mechanism by which administrators could load apps that are not in the Google Play Store, currently the only way to install apps outside of the afore mentioned Developer Mode. For now, it appears that this would only be an Enterprise level administrator feature in the platform.