Keystone Agent is running by launchd on macOS, usually modifying defaults can stop it from running: defaults write com.google.Keystone.Agent checkInterval

Keystone Agent is running by launchd on macOS, usually modifying defaults can stop it from running: defaults write com.google.Keystone.Agent checkInterval 0 However, this won't remove the agent from the system, and I think there's no way to be sure Google won't change this configuration key in an update (or even overriding its value).