Merge //ios/chrome/browser/signin:{authentication_service,signin}.

ios/chrome/browser/signin/authentication_service_unittest.mm

 // Copyright 2013 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include <memory>
 
 #include "base/memory/ptr_util.h"
 #include "base/run_loop.h"
 #include "base/strings/sys_string_conversions.h"
 #include "components/browser_sync/profile_sync_service_mock.h"
@@ skipping 117 matching lines @@
         ->AddObserver(this);
   }
 
   std::unique_ptr<syncable_prefs::PrefServiceSyncable> CreatePrefService() {
     syncable_prefs::PrefServiceMockFactory factory;
     scoped_refptr<user_prefs::PrefRegistrySyncable> registry(
         new user_prefs::PrefRegistrySyncable);
     std::unique_ptr<syncable_prefs::PrefServiceSyncable> prefs =
         factory.CreateSyncable(registry.get());
     RegisterBrowserStatePrefs(registry.get());
-    AuthenticationService::RegisterPrefs(registry.get());
     return prefs;
   }
 
   void TearDown() override {
     OAuth2TokenServiceFactory::GetForBrowserState(browser_state_.get())
         ->RemoveObserver(this);
     authentication_service_->Shutdown();
     authentication_service_.reset();
     browser_state_.reset();
     TestingApplicationContext::GetGlobal()->SetChromeBrowserStateManager(
@@ skipping 592 matching lines @@
   NSDictionary* user_info = [NSDictionary dictionary];
   SetCachedMDMInfo(identity_, user_info);
 
   EXPECT_CALL(*identity_service_,
               HandleMDMNotification(identity_, user_info, _))
       .WillOnce(Return(true));
 
   EXPECT_TRUE(
       authentication_service_->ShowMDMErrorDialogForIdentity(identity_));
 }