This is an interesting feature concept that I can certainly see the use case for, but I tend to think something like Google Tag Manager would be a better solution for someone needing that functionality.
Google will provide you with a snippet of code that will something like this:
<link href="https://fonts.googleapis.com/css?family=Roboto" rel="stylesheet">
This will go in the Head text box. This will embed the font on the page. From there, you’ll need to use CSS to apply the font to the text on the page.
