Follow below steps to connect PlayStation 4 DualShock 4 wireless controller to your Android smartphone or Chromebook via Bluetooth.
Content Summary
Activate bluetooth on PS4 Controller
Open or Start Bluetooth on your device
Start Playing
Reference
Activate bluetooth on PS4 Controller
Hold down SHARE button and PlayStation logo button together until the white light bar begins flashing indicate it enter the pairing mode.
Open or Start Bluetooth on your device
For Google Android smartphone
Go to Settings app > Bluetooth settings under Connected Devices > Select Pair new device.
For Samsung Android smartphone
Go to Settings app > Bluetooth settings under Connections > Select Pair new device.
For Chromebook
Step 1: Go to Settings app > main settings page, click Bluetooth setting.
Step 2: Select Wireless Controller from the list of available devices.
For Steam Link
Step 1: Find Wireless Controller of type gamepad in the bluetooth device list
Step 2: Press the (A) button to pair with the PS4 controller
Start Playing
Some games will have the profile for PS4 wireless controllers already in there but not all games are compatible with third-party controllers, go to game’s settings look for controller options and manually assign all of the buttons if needed If no built-in support for controllers and you’re rooted, use Tincore Keymapper to make your DualShock 4 controller work with it.
Reference
Steam Support: PlayStation 4 Controller