[Payments] Show what's missing for incomplete payment methods.

chrome/browser/ui/views/payments/credit_card_editor_view_controller.cc

 // Copyright 2017 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/ui/views/payments/credit_card_editor_view_controller.h"
 
 #include <memory>
 #include <string>
 #include <utility>
 #include <vector>
@@ skipping 186 matching lines @@
               autofill::AutofillType(field.second.type).group());
     ValidatingCombobox* combobox = field.first;
     if (combobox->invalid())
       return false;
 
     credit_card.SetInfo(autofill::AutofillType(field.second.type),
                         combobox->GetTextForRow(combobox->selected_index()),
                         locale);
   }
 
-  // TODO(mathp): Display global error message.
-  if (!credit_card.IsValid())
+  // TODO(crbug.com/711365): Display global error message.
+  if (autofill::GetCompletionStatusForCard(credit_card, locale) !=
+      autofill::CREDIT_CARD_COMPLETE) {
     return false;
+  }
 
   if (!credit_card_to_edit_) {
     // Add the card (will not add a duplicate).
     state()->GetPersonalDataManager()->AddCreditCard(credit_card);
     std::move(on_added_).Run(credit_card);
   } else {
     // We were in edit mode. Copy the data from the temporary object to retain
     // the edited object's other properties (use count, use date, guid, etc.).
     for (const auto& field : text_fields()) {
       credit_card_to_edit_->SetInfo(
@@ skipping 93 matching lines @@
   bool is_required_valid = !field_.required;
   const base::string16 displayed_message =
       is_required_valid ? base::ASCIIToUTF16("")
                         : l10n_util::GetStringUTF16(
                               IDS_PAYMENTS_FIELD_REQUIRED_VALIDATION_MESSAGE);
   controller_->DisplayErrorMessageForField(field_, displayed_message);
   return is_required_valid;
 }
 
 }  // namespace payments