[ObjC ARC] Converts components/autofill/ios/browser:browser to ARC.

components/autofill/ios/browser/credit_card_util.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 "components/autofill/ios/browser/credit_card_util.h"
 
 #include "base/strings/sys_string_conversions.h"
 #include "components/autofill/core/browser/autofill_type.h"
 #include "components/autofill/core/browser/credit_card.h"
 
+#if !defined(__has_feature) || !__has_feature(objc_arc)
+#error "This file requires ARC support."
+#endif
+
 namespace autofill {
 
 NSString* GetCreditCardName(const CreditCard& credit_card,
                             const std::string& locale) {
   return base::SysUTF16ToNSString(credit_card.GetInfo(
       autofill::AutofillType(autofill::CREDIT_CARD_NAME_FULL), locale));
 }
 
 NSString* GetCreditCardObfuscatedNumber(const CreditCard& credit_card) {
   return base::SysUTF16ToNSString(credit_card.TypeAndLastFourDigits());
 }
 
 NSDateComponents* GetCreditCardExpirationDate(const CreditCard& credit_card) {
-  NSDateComponents* expiration_date =
-      [[[NSDateComponents alloc] init] autorelease];
+  NSDateComponents* expiration_date = [[NSDateComponents alloc] init];
   expiration_date.year = credit_card.expiration_year();
   expiration_date.month = credit_card.expiration_month();
   return expiration_date;
 }
 
 BOOL IsCreditCardLocal(const CreditCard& credit_card) {
   return credit_card.record_type() == autofill::CreditCard::LOCAL_CARD;
 }
 
 }  // namespace autofill