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

ios/chrome/browser/ui/settings/physical_web_collection_view_controller_unittest.mm

 // Copyright 2016 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/physical_web_collection_view_controller.h"
 
 #include <memory>
 
 #include "base/files/file_path.h"
 #include "base/memory/ptr_util.h"
 #include "base/memory/ref_counted.h"
 #include "base/message_loop/message_loop.h"
 #include "components/prefs/pref_registry_simple.h"
 #include "components/prefs/pref_service.h"
 #include "components/sync_preferences/pref_service_mock_factory.h"
 #include "ios/chrome/browser/physical_web/physical_web_constants.h"
 #include "ios/chrome/browser/pref_names.h"
 #import "ios/chrome/browser/ui/collection_view/cells/collection_view_footer_item.h"
 #import "ios/chrome/browser/ui/collection_view/cells/collection_view_switch_item.h"
 #import "ios/chrome/browser/ui/collection_view/collection_view_controller_test.h"
 #include "ios/chrome/grit/ios_chromium_strings.h"
 #include "ios/chrome/grit/ios_strings.h"
 
+#if !defined(__has_feature) || !__has_feature(objc_arc)
+#error "This file requires ARC support."
+#endif
+
 @interface PhysicalWebCollectionViewController (ExposedForTesting)
 - (void)updatePhysicalWebEnabled:(BOOL)enabled;
 @end
 
 namespace {
 
 class PhysicalWebCollectionViewControllerTest
     : public CollectionViewControllerTest {
  protected:
   void SetUp() override {
     CollectionViewControllerTest::SetUp();
     pref_service_ = CreateLocalState();
     CreateController();
   }
 
-  CollectionViewController* NewController() override {
-    physicalWebController_.reset([[PhysicalWebCollectionViewController alloc]
-        initWithPrefs:pref_service_.get()]);
-    return [physicalWebController_ retain];
+  CollectionViewController* InstantiateController() override {
+    physicalWebController_ = [[PhysicalWebCollectionViewController alloc]
+        initWithPrefs:pref_service_.get()];
+    return physicalWebController_;
   }
 
   std::unique_ptr<PrefService> CreateLocalState() {
     scoped_refptr<PrefRegistrySimple> registry(new PrefRegistrySimple());
     registry->RegisterIntegerPref(prefs::kIosPhysicalWebEnabled,
                                   physical_web::kPhysicalWebOnboarding);
 
     sync_preferences::PrefServiceMockFactory factory;
     base::FilePath path("PhysicalWebCollectionViewControllerTest.pref");
     factory.SetUserPrefsFile(path, message_loop_.task_runner().get());
     return factory.Create(registry.get());
   }
 
   base::MessageLoopForUI message_loop_;
   std::unique_ptr<PrefService> pref_service_;
-  base::scoped_nsobject<PhysicalWebCollectionViewController>
-      physicalWebController_;
+  PhysicalWebCollectionViewController* physicalWebController_;
 };
 
 // Tests PhysicalWebCollectionViewController is set up with all appropriate
 // items and sections.
 TEST_F(PhysicalWebCollectionViewControllerTest, TestModel) {
   CheckController();
   EXPECT_EQ(2, NumberOfSections());
 
   // First section should have no section header and one row (switch item).
   EXPECT_EQ(1, NumberOfItemsInSection(0));
   CheckSwitchCellStateAndTitleWithId(NO, IDS_IOS_OPTIONS_ENABLE_PHYSICAL_WEB, 0,
                                      0);
 
   // Section section should have no section header and one row (footer item).
   EXPECT_EQ(1, NumberOfItemsInSection(1));
   CheckSectionFooterWithId(IDS_IOS_OPTIONS_ENABLE_PHYSICAL_WEB_DETAILS, 1);
 }
 
 TEST_F(PhysicalWebCollectionViewControllerTest, TestUpdateCheckedState) {
   CheckController();
   ASSERT_EQ(2, NumberOfSections());
   ASSERT_EQ(1, NumberOfItemsInSection(0));
 
   [physicalWebController_
       updatePhysicalWebEnabled:physical_web::kPhysicalWebOn];
 }
 
 }  // namespace