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

ios/chrome/browser/ui/settings/block_popups_collection_view_controller_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.
 
 #import <Foundation/Foundation.h>
 
 #include <memory>
 
 #include "base/message_loop/message_loop.h"
 #include "base/strings/sys_string_conversions.h"
 #import "base/test/ios/wait_util.h"
 #include "components/content_settings/core/browser/host_content_settings_map.h"
 #include "ios/chrome/browser/browser_state/test_chrome_browser_state.h"
 #include "ios/chrome/browser/content_settings/host_content_settings_map_factory.h"
 #import "ios/chrome/browser/ui/collection_view/collection_view_controller_test.h"
 #import "ios/chrome/browser/ui/settings/block_popups_collection_view_controller.h"
 #include "ios/chrome/grit/ios_strings.h"
 #include "ios/web/public/test/test_web_thread_bundle.h"
 #include "testing/gtest/include/gtest/gtest.h"
 #include "url/gurl.h"
 
+#if !defined(__has_feature) || !__has_feature(objc_arc)
+#error "This file requires ARC support."
+#endif
+
 @interface SettingsRootCollectionViewController (ExposedForTesting)
 - (void)editButtonPressed;
 @end
 
 namespace {
 
 const char* kAllowedPattern = "[*.]example.com";
 const char* kAllowedURL = "http://example.com";
 
 class BlockPopupsCollectionViewControllerTest
     : public CollectionViewControllerTest {
  protected:
   void SetUp() override {
     CollectionViewControllerTest::SetUp();
     TestChromeBrowserState::Builder test_cbs_builder;
     chrome_browser_state_ = test_cbs_builder.Build();
   }
 
-  CollectionViewController* NewController() override NS_RETURNS_RETAINED {
+  CollectionViewController* InstantiateController() override {
     return [[BlockPopupsCollectionViewController alloc]
         initWithBrowserState:chrome_browser_state_.get()];
   }
 
   void SetDisallowPopups() {
     ios::HostContentSettingsMapFactory::GetForBrowserState(
         chrome_browser_state_.get())
         ->SetDefaultContentSetting(CONTENT_SETTINGS_TYPE_POPUPS,
                                    CONTENT_SETTING_BLOCK);
   }
@@ skipping 113 matching lines @@
   // Verify that there are no longer any allowed patterns in |profile_|.
   ContentSettingsForOneType final_entries;
   ios::HostContentSettingsMapFactory::GetForBrowserState(
       chrome_browser_state_.get())
       ->GetSettingsForOneType(CONTENT_SETTINGS_TYPE_POPUPS, std::string(),
                               &final_entries);
   EXPECT_EQ(initial_entries.size(), final_entries.size());
 }
 
 }  // namespace