This is not much of a surprise since it is a well-know fact that Google uses Ubuntu (albeit with modifications) in their campuses. Not only that, it was confirmed by Canonical themselves last year that Google is a paying customer of Ubuntu Advantage program.
Google's Project Tango promo video feature Ubuntu
For those who are wondering, Project Tango is Google's attempt at creating mobile devices with a human-scale understanding of space and motion. See Google's Project Tango intro video below (skip to 2:07 to watch the Ubuntu reference).
"Our team has been working with universities, research labs, and industrial partners spanning nine countries around the world to build on the last decade of research in robotics and computer vision, concentrating that technology into a unique mobile device. We are putting early prototypes into the hands of developers that can imagine the possibilities and help bring those ideas into reality." Interested? Sign up here.