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

ios/chrome/browser/payments/payment_request_test_util.mm

 // Copyright 2017 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/browser/payments/payment_request_test_util.h"
 
 #include "base/guid.h"
 #include "base/memory/ptr_util.h"
 #include "base/strings/utf_string_conversions.h"
 #include "components/autofill/core/browser/autofill_profile.h"
 #include "components/autofill/core/browser/autofill_test_utils.h"
 #include "components/autofill/core/browser/credit_card.h"
 #include "components/autofill/core/browser/test_personal_data_manager.h"
 #include "ios/chrome/browser/payments/payment_request.h"
 #include "ios/web/public/payments/payment_request.h"
 
+#if !defined(__has_feature) || !__has_feature(objc_arc)
+#error "This file requires ARC support."
+#endif
+
 namespace payment_request_test_util {
 
 web::PaymentRequest CreateTestWebPaymentRequest() {
   web::PaymentRequest web_payment_request;
   web::PaymentMethodData method_datum;
   method_datum.supported_methods.push_back(base::ASCIIToUTF16("visa"));
   web_payment_request.method_data.push_back(method_datum);
   web_payment_request.details.total.label = base::ASCIIToUTF16("Total");
   web_payment_request.details.total.amount.value = base::ASCIIToUTF16("1.00");
   web_payment_request.details.total.amount.currency = base::ASCIIToUTF16("USD");
@@ skipping 53 matching lines @@
   personal_data_manager->AddTestingProfile(profile.get());
 
   web::PaymentRequest web_payment_request = CreateTestWebPaymentRequest();
 
   return base::MakeUnique<PaymentRequest>(
       base::MakeUnique<web::PaymentRequest>(web_payment_request),
       personal_data_manager.get());
 }
 
 }  // namespace payment_request_test_util