**Please not this method no longer works with current versions of Divi – 2.7+ – See comment from Dani Dwiputra below for update**
There are many ways to add Google fonts to your Divi website, but most will not allow you to select those fonts in the Divi Builder font selection dropdowns or via the Divi customizer. By following the method below in the video tutorial, you can achieve both. The process was patched together from posts in the Elegant Themes support* which is a great source of info and of course, support!
This method does require modifying the functions.php file within a Divi child theme, which if done wrong will break your site. If you are going to use this method, please make sure you have taken a backup of your Divi Theme before you start.