[ObjC ARC] Converts ios/chrome/browser/ui/settings:unit_tests to ARC.

ios/chrome/browser/ui/settings/search_engine_settings_collection_view_controller_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.
 
 #import "ios/chrome/browser/ui/settings/search_engine_settings_collection_view_controller.h"
 
 #include <memory>
 
 #include "base/compiler_specific.h"
 #include "base/mac/foundation_util.h"
 #include "base/strings/sys_string_conversions.h"
 #include "base/strings/utf_string_conversions.h"
 #include "components/search_engines/template_url_service.h"
 #include "components/sync_preferences/testing_pref_service_syncable.h"
 #include "ios/chrome/browser/browser_state/test_chrome_browser_state.h"
 #include "ios/chrome/browser/search_engines/template_url_service_factory.h"
 #import "ios/chrome/browser/ui/collection_view/cells/collection_view_text_item.h"
 #import "ios/chrome/browser/ui/collection_view/collection_view_controller_test.h"
 #import "ios/third_party/material_components_ios/src/components/CollectionCells/src/MaterialCollectionCells.h"
 #include "ios/web/public/test/test_web_thread_bundle.h"
 #include "testing/gtest/include/gtest/gtest.h"
 #import "testing/gtest_mac.h"
 
+#if !defined(__has_feature) || !__has_feature(objc_arc)
+#error "This file requires ARC support."
+#endif
+
 namespace {
 
 class SearchEngineSettingsCollectionViewControllerTest
     : public CollectionViewControllerTest {
  protected:
   void SetUp() override {
     CollectionViewControllerTest::SetUp();
     TestChromeBrowserState::Builder test_cbs_builder;
     test_cbs_builder.AddTestingFactory(
         ios::TemplateURLServiceFactory::GetInstance(),
         ios::TemplateURLServiceFactory::GetDefaultFactory());
     chrome_browser_state_ = test_cbs_builder.Build();
     DefaultSearchManager::SetFallbackSearchEnginesDisabledForTesting(true);
     template_url_service_ = ios::TemplateURLServiceFactory::GetForBrowserState(
         chrome_browser_state_.get());
     template_url_service_->Load();
   }
 
-  CollectionViewController* NewController() override NS_RETURNS_RETAINED {
+  CollectionViewController* InstantiateController() override {
     return [[SearchEngineSettingsCollectionViewController alloc]
         initWithBrowserState:chrome_browser_state_.get()];
   }
 
   std::unique_ptr<TemplateURL> NewTemplateUrl(const std::string& shortName) {
     TemplateURLData data;
     data.SetShortName(base::ASCIIToUTF16(shortName));
     return std::unique_ptr<TemplateURL>(new TemplateURL(data));
   }
 
@@ skipping 81 matching lines @@
           DefaultSearchManager::kDefaultSearchProviderDataPrefName);
   EXPECT_TRUE(searchProviderDict);
   base::string16 shortName;
   EXPECT_TRUE(searchProviderDict->GetString(DefaultSearchManager::kShortName,
                                             &shortName));
   EXPECT_EQ(url->short_name(), shortName);
   CheckModelMatchesTemplateURLs();
 }
 
 }  // namespace