I've noticed that you can now add your own fonts to Google Docs. When clicking the More fonts... button, the following dialog box appears:
On the right hand side, the My fonts section shows some custom fonts that are installed on my Mac. When I select Avenir, the additional weights (Light, Bold, Heavy etc) are not available.
Is it possible to install the full font family without installing an extension? I can't see any additional options to add more.