How to use Google open-source code in Xamarin.Android?

I want to make use of Google's new datetimepicker, as seen in the Google Calendar app. Google has open-sourced the code here:

https://android.googlesource.com/platform/frameworks/opt/datetimepicker/

What's the process for making use of this excellent resource in a Xamarin.Android project? It is provided as source code and resources, not as a jar.