[ObjC ARC] Converts ios/chrome/test:test_support to ARC.

ios/chrome/test/ios_chrome_unit_test_suite.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 "ios/chrome/test/ios_chrome_unit_test_suite.h"
 
 #include "base/macros.h"
 #include "base/metrics/user_metrics.h"
 #include "base/path_service.h"
 #include "base/test/test_simple_task_runner.h"
 #include "components/content_settings/core/common/content_settings_pattern.h"
 #include "ios/chrome/browser/browser_state/browser_state_keyed_service_factories.h"
 #include "ios/chrome/browser/chrome_paths.h"
 #include "ios/chrome/browser/chrome_url_constants.h"
 #include "ios/chrome/test/testing_application_context.h"
 #import "ios/public/provider/chrome/browser/chrome_browser_provider.h"
 #include "ios/public/provider/chrome/browser/test_chrome_provider_initializer.h"
 #import "ios/web/public/web_client.h"
 #include "testing/gtest/include/gtest/gtest.h"
 #include "ui/base/resource/resource_bundle.h"
 #include "ui/base/ui_base_paths.h"
 #include "url/url_util.h"
 
+#if !defined(__has_feature) || !__has_feature(objc_arc)
+#error "This file requires ARC support."
+#endif
+
 namespace {
 
 class IOSChromeUnitTestSuiteInitializer
     : public testing::EmptyTestEventListener {
  public:
   IOSChromeUnitTestSuiteInitializer() {}
   ~IOSChromeUnitTestSuiteInitializer() override {}
 
   void OnTestStart(const testing::TestInfo& test_info) override {
     DCHECK(!ios::GetChromeBrowserProvider());
@@ skipping 46 matching lines @@
   // Register a SingleThreadTaskRunner for base::RecordAction as overridding
   // it in individual tests is unsafe (as there is no way to unregister).
   base::SetRecordActionTaskRunner(action_task_runner_);
 
   ios::RegisterPathProvider();
   ui::RegisterPathProvider();
   url::AddStandardScheme(kChromeUIScheme, url::SCHEME_WITHOUT_PORT);
   ContentSettingsPattern::SetNonWildcardDomainNonPortScheme(
       kDummyExtensionScheme);
 }