I'm using Galaxy Note 2
Nowadays, every link in FB app and in Whatsapp is opened in the native browser
I want to make Chrome the defualt browser for all actions including these two apps.
How can I do this?
While j0chn's description works (and also does work for other "default apps"), it might not be the most user-friendly approach. As Android itself does not offer anything else, you might want to pick a helper. Default App Manager is such a helper:
Default App Manager (Source: Google Play); Click images to enlarge
As the screenshots show, this app lists up default apps defined and lets you clear those defaults -- but it also lets you define them.