DETROIT — The development of self-driving cars in recent years has been primarily a competition between technology companies and automakers working independently of each other.

But that dynamic changed markedly on Tuesday, when Google said it would expand its testing of autonomous vehicles by installing its technology in a fleet of minivans made by Fiat Chrysler.

The deal is the most prominent example yet of a Silicon Valley company collaborating with a traditional automaker on self-driving vehicles.

It could also prove to be a breakthrough in the generally wary relationship between technology and auto companies, and prompt more collaborative efforts.