SAN FRANCISCO — In the furiously paced, headline-grabbing legal feud between Google's driverless car unit Waymo and rival Uber, there are huge sums at stake, big Silicon Valley egos, and armies of high-octane lawyers on either side.

And then there is John Cooper.

A lifetime litigator at the midsize San Francisco law firm Farella Braun + Martel, Cooper was tapped in April to be the “special master” in Waymo's trade secrets case against Uber, putting him at the center of what could be seen as a battle for the future of the autonomous vehicle industry.