There is a small amount of usage of the above method:

chrome/browser/profiles/profile_manager.cc:1283:      ->SetupInvalidationsOnProfileLoad(invalidation_service);
components/signin/core/browser/account_fetcher_service.cc:124:  SetupInvalidationsOnProfileLoad(nullptr);
ios/chrome/browser/browser_state/chrome_browser_state_manager_impl.cc:223:      ->SetupInvalidationsOnProfileLoad(invalidation_service);

It's not immediately clear what this method is doing or how to enable equivalent functionality via the Identity Service client library.