Autofill: Better recognize credit card type fields.

components/autofill/core/browser/credit_card_field.h

Index: components/autofill/core/browser/credit_card_field.h
diff --git a/components/autofill/core/browser/credit_card_field.h b/components/autofill/core/browser/credit_card_field.h
index 2d8ba6f52c2c5cf665bc1a340c69681b8ee98c00..0f94f3edd3ec7b48e0e87579e3d4c92141a9e7da 100644
--- a/components/autofill/core/browser/credit_card_field.h
+++ b/components/autofill/core/browser/credit_card_field.h
@@ -40,6 +40,10 @@ class CreditCardField : public FormField {
   // the next few years.
   static bool LikelyCardYearSelectField(AutofillScanner* scanner);
 
+  // Returns true if |scanner| points to a <select> field that contains credit
+  // card type options.
+  static bool LikelyCardTypeSelectField(AutofillScanner* scanner);
+
   CreditCardField();
 
   // Parses the expiration month/year/date fields. Returns true if it finds