With ChromeOS, you can sign in to or unlock the device when your Android phone is nearby.
- A phone with Android 5.0+, Smart Lock, and Bluetooth. Additionally, the phone must have a lock screen, be unlocked, and be within 100 feet of the ChromeOS device.
- A Chromebook with Chrome OS version 40+ and Bluetooth.
To do it…
 On the ChromeOS device, go into Settings.
 In the People section, select Screen lock.
 You’ll be prompted for your login password. Type in the password and then select Confirm.
 Tap or click the Setup button next to Smart Lock.
 Follow the onscreen instructions.