[Payment Request] Generic edit form

ios/chrome/browser/payments/payment_method_selection_view_controller.mm

 // Copyright 2016 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.
 
 #import "ios/chrome/browser/payments/payment_method_selection_view_controller.h"
 
 #include "base/mac/foundation_util.h"
 #include "base/strings/sys_string_conversions.h"
 #include "components/autofill/core/browser/autofill_data_util.h"
 #include "components/autofill/core/browser/credit_card.h"
@@ skipping 153 matching lines @@
     // Update the reference to the selected item.
     _selectedItem = newlySelectedItem;
 
     // Notify the delegate of the selection.
     NSInteger index = [model indexInItemTypeForIndexPath:indexPath];
     DCHECK(index < (NSInteger)_paymentRequest->credit_cards().size());
     [_delegate
         paymentMethodSelectionViewController:self
                       didSelectPaymentMethod:_paymentRequest
                                                  ->credit_cards()[index]];
+  } else if (item.type == ItemTypeAddMethod) {
+    [_delegate paymentMethodSelectionViewControllerDidSelectAddCard:self];
   }
-  // TODO(crbug.com/602666): Present a credit card addition UI when
-  // itemType == ItemTypeAddMethod.
 }
 
 #pragma mark MDCCollectionViewStylingDelegate
 
 - (CGFloat)collectionView:(UICollectionView*)collectionView
     cellHeightAtIndexPath:(NSIndexPath*)indexPath {
   CollectionViewItem* item =
       [self.collectionViewModel itemAtIndexPath:indexPath];
   switch (item.type) {
     case ItemTypePaymentMethod:
       return MDCCellDefaultTwoLineHeight;
     case ItemTypeAddMethod:
       return [MDCCollectionViewCell
           cr_preferredHeightForWidth:CGRectGetWidth(collectionView.bounds)
                              forItem:item];
     default:
       NOTREACHED();
       return MDCCellDefaultOneLineHeight;
   }
 }
 
 @end