Simplify Autofill Scanner semantics

chrome/browser/autofill/credit_card_field.cc

 // Copyright (c) 2011 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 "chrome/browser/autofill/credit_card_field.h"
 
 #include <stddef.h>
 
 #include "base/logging.h"
 #include "base/memory/scoped_ptr.h"
 #include "base/string16.h"
 #include "base/string_util.h"
 #include "base/utf_string_conversions.h"
 #include "chrome/browser/autofill/autofill_ecml.h"
 #include "chrome/browser/autofill/autofill_field.h"
 #include "chrome/browser/autofill/autofill_scanner.h"
 #include "chrome/browser/autofill/field_types.h"
 #include "grit/autofill_resources.h"
 #include "ui/base/l10n/l10n_util.h"
 
 using autofill::GetEcmlPattern;
 
 // static
 FormField* CreditCardField::Parse(AutofillScanner* scanner,
                                         bool is_ecml) {
   if (scanner->IsEnd())
     return NULL;
 
   scoped_ptr<CreditCardField> credit_card_field(new CreditCardField);
-  scanner->SaveCursor();
+  size_t saved_cursor = scanner->SaveCursor();
 
   // Credit card fields can appear in many different orders.
   // We loop until no more credit card related fields are found, see |break| at
   // bottom of the loop.
   for (int fields = 0; !scanner->IsEnd(); ++fields) {
     // Sometimes the cardholder field is just labeled "name". Unfortunately this
     // is a dangerously generic word to search for, since it will often match a
     // name (not cardholder name) field before or after credit card fields. So
     // we search for "name" only when we've already parsed at least one other
     // credit card field and haven't yet parsed the expiration date (which
@@ skipping 83 matching lines @@
            credit_card_field->expiration_month_->IsEmpty()) &&
           ParseFieldSpecifics(scanner, pattern, MATCH_DEFAULT | MATCH_SELECT,
                               &credit_card_field->expiration_month_)) {
         if (is_ecml)
           pattern = GetEcmlPattern(kEcmlCardExpireYear);
         else
           pattern = l10n_util::GetStringUTF16(IDS_AUTOFILL_EXPIRATION_DATE_RE);
 
         if (!ParseFieldSpecifics(scanner, pattern, MATCH_DEFAULT | MATCH_SELECT,
                                  &credit_card_field->expiration_year_)) {
-          scanner->Rewind();
+          scanner->RewindTo(saved_cursor);
           return NULL;
         }
         continue;
       }
     }
 
     if (ParseFieldSpecifics(scanner, GetEcmlPattern(kEcmlCardExpireDay),
                             MATCH_DEFAULT | MATCH_SELECT, NULL)) {
       continue;
     }
@@ skipping 27 matching lines @@
   // the cvc and date were found independently they are returned.
   if ((credit_card_field->number_ || credit_card_field->verification_) &&
       credit_card_field->expiration_month_ &&
       (credit_card_field->expiration_year_ ||
       (LowerCaseEqualsASCII(
            credit_card_field->expiration_month_->form_control_type,
            "month")))) {
     return credit_card_field.release();
   }
 
-  scanner->Rewind();
+  scanner->RewindTo(saved_cursor);
   return NULL;
 }
 
 CreditCardField::CreditCardField()
     : cardholder_(NULL),
       cardholder_last_(NULL),
       type_(NULL),
       number_(NULL),
       verification_(NULL),
       expiration_month_(NULL),
@@ skipping 10 matching lines @@
   if (cardholder_last_ == NULL)
     ok = ok && AddClassification(cardholder_, CREDIT_CARD_NAME, map);
 
   ok = ok && AddClassification(type_, CREDIT_CARD_TYPE, map);
   ok = ok && AddClassification(expiration_month_, CREDIT_CARD_EXP_MONTH, map);
   ok = ok && AddClassification(expiration_year_,
                                CREDIT_CARD_EXP_4_DIGIT_YEAR,
                                map);
   return ok;
 }