Annotates functions returning retained objects.

components/signin/ios/browser/account_consistency_service_unittest.mm

 // Copyright 2015 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 "components/signin/ios/browser/account_consistency_service.h"
 
 #import <WebKit/WebKit.h>
 
 #include <memory>
 
@@ skipping 44 matching lines @@
       SigninManager* signin_manager)
       : AccountConsistencyService(browser_state,
                                   account_reconcilor,
                                   cookie_settings,
                                   gaia_cookie_manager_service,
                                   signin_client,
                                   signin_manager),
         mock_web_view_(nil) {}
 
  private:
-  WKWebView* CreateWKWebView() override {
+  WKWebView* CreateWKWebView() override NS_RETURNS_RETAINED {
     if (!mock_web_view_) {
       mock_web_view_ = [OCMockObject niceMockForClass:[WKWebView class]];
     }
     return [mock_web_view_ retain];
   }
   id mock_web_view_;
 };
 
 // Mock AccountReconcilor to catch call to OnReceivedManageAccountsResponse.
 class MockAccountReconcilor : public AccountReconcilor {
@@ skipping 363 matching lines @@
 // Tests that main domains are added to the internal map when cookies are set in
 // reaction to signin.
 TEST_F(AccountConsistencyServiceTest, SigninAddCookieOnMainDomains) {
   AddPageLoadedExpectation(kGoogleUrl, true /* continue_navigation */);
   AddPageLoadedExpectation(kYoutubeUrl, true /* continue_navigation */);
   SignIn();
 
   CheckDomainHasCookie(kGoogleDomain);
   CheckDomainHasCookie(kYoutubeDomain);
 }