[Autofill] Add a separate enumeration for HTML field type hints.

components/autofill/core/browser/autofill_data_model.cc

 // Copyright 2013 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/core/browser/autofill_data_model.h"
 
 #include "base/basictypes.h"
 #include "base/logging.h"
 #include "base/strings/string_number_conversions.h"
 #include "base/strings/string_util.h"
@@ skipping 140 matching lines @@
       // not found.
       value = field->option_values[i];
     }
   }
 
   if (!value.empty()) {
     field->value = value;
     return;
   }
 
-  NativeFieldType native_type = type.native_type();
-  if (native_type == ADDRESS_HOME_STATE ||
-      native_type == ADDRESS_BILLING_STATE) {
+  NativeFieldType native_type = type.GetEquivalentNativeType();
+  if (native_type == ADDRESS_HOME_STATE) {
     FillStateSelectControl(field_text, field);
-  } else if (native_type == ADDRESS_HOME_COUNTRY ||
-             native_type == ADDRESS_BILLING_COUNTRY) {
+  } else if (native_type == ADDRESS_HOME_COUNTRY) {
     FillCountrySelectControl(app_locale, field);
   } else if (native_type == CREDIT_CARD_EXP_MONTH) {
     FillExpirationMonthSelectControl(field_text, field);
   } else if (native_type == CREDIT_CARD_EXP_4_DIGIT_YEAR) {
     // Attempt to fill the year as a 2-digit year.  This compensates for the
     // fact that our heuristics do not always correctly detect when a website
     // requests a 2-digit rather than a 4-digit year.
     FillSelectControl(AutofillType(CREDIT_CARD_EXP_2_DIGIT_YEAR), app_locale,
                       field);
   } else if (native_type == CREDIT_CARD_TYPE) {
     FillCreditCardTypeSelectControl(field_text, field);
   }
 }
 
 bool AutofillDataModel::FillCountrySelectControl(
     const std::string& app_locale,
     FormFieldData* field_data) const {
   return false;
 }
 
 bool AutofillDataModel::IsVerified() const {
   return !origin_.empty() && !GURL(origin_).is_valid();
 }
 
 }  // namespace autofill