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

components/autofill/core/browser/credit_card.cc

Index: components/autofill/core/browser/credit_card.cc
diff --git a/components/autofill/core/browser/credit_card.cc b/components/autofill/core/browser/credit_card.cc
index 2a4e8b6cbebe65079417bd575bb4ca994e00eb92..03cdab3d102c1660d65ecd2a53b53a998f0d98ea 100644
--- a/components/autofill/core/browser/credit_card.cc
+++ b/components/autofill/core/browser/credit_card.cc
@@ -371,16 +371,17 @@ void CreditCard::SetRawInfo(NativeFieldType type,
 
 base::string16 CreditCard::GetInfo(const AutofillType& type,
                                    const std::string& app_locale) const {
-  if (type.native_type() == CREDIT_CARD_NUMBER)
+  NativeFieldType native_type = type.GetEquivalentNativeType();
+  if (native_type == CREDIT_CARD_NUMBER)
     return StripSeparators(number_);
 
-  return GetRawInfo(type.native_type());
+  return GetRawInfo(native_type);
 }
 
 bool CreditCard::SetInfo(const AutofillType& type,
                          const base::string16& value,
                          const std::string& app_locale) {
-  NativeFieldType native_type = type.native_type();
+  NativeFieldType native_type = type.GetEquivalentNativeType();
   if (native_type == CREDIT_CARD_NUMBER)
     SetRawInfo(native_type, StripSeparators(value));
   else if (native_type == CREDIT_CARD_EXP_MONTH)