You can follow these simple steps on setting google chrome as your default browser:
If you are using IOS - iPhone or iPad:
Click the Settings app, next scroll down and click Chrome.
Click the Default Browser App, then click Chrome.
If you are using Android:
Click the Settings app, then click Apps.
Click Chrome, locate Defaults and click Browser app.
Click Chrome.
The above can only be completed if you have downloaded the chrome application onto your handset.