Autofill: Set requirements for number of recognized fields in an autofillable form

components/autofill/core/browser/email_field.cc

Index: components/autofill/core/browser/email_field.cc
diff --git a/components/autofill/core/browser/email_field.cc b/components/autofill/core/browser/email_field.cc
index cfe4a1a187405a2fc068c42243a87bcb136a75c7..9c67c8892ad91658253ee2ffad7931ca7e9ff4fb 100644
--- a/components/autofill/core/browser/email_field.cc
+++ b/components/autofill/core/browser/email_field.cc
@@ -4,6 +4,7 @@
 
 #include "components/autofill/core/browser/email_field.h"
 
+#include "base/logging.h"
 #include "base/strings/utf_string_conversions.h"
 #include "components/autofill/core/browser/autofill_regex_constants.h"
 #include "components/autofill/core/browser/autofill_scanner.h"
@@ -22,10 +23,15 @@ scoped_ptr<FormField> EmailField::Parse(AutofillScanner* scanner) {
 }
 
 EmailField::EmailField(const AutofillField* field) : field_(field) {
+  DCHECK(field);
 }
 
 bool EmailField::ClassifyField(ServerFieldTypeMap* map) const {
   return AddClassification(field_, EMAIL_ADDRESS, map);
 }
 
+size_t EmailField::FieldCount() const {
+  return 1;
+}
+
 }  // namespace autofill