[Payment Request] Contact Info editor

ios/chrome/browser/ui/payments/payment_request_edit_view_controller.mm

 // 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.
 
 #import "ios/chrome/browser/ui/payments/payment_request_edit_view_controller.h"
 
 #include "base/logging.h"
 #import "base/mac/foundation_util.h"
 #include "base/strings/sys_string_conversions.h"
 #include "components/strings/grit/components_strings.h"
@@ skipping 530 matching lines @@
   if ([self.collectionViewModel
           hasSectionForSectionIdentifier:SectionIdentifierHeader])
     index--;
   DCHECK(index >= 0 && index < static_cast<NSInteger>(self.fields.count));
   EditorField* field = [self.fields objectAtIndex:index];
 
   // If a selector field is selected, blur the focused text field.
   if (field.fieldType == EditorFieldTypeSelector)
     [[_currentEditingCell textField] resignFirstResponder];
 
-  [_delegate paymentRequestEditViewController:self didSelectField:field];
+  if ([self.delegate respondsToSelector:@selector
+                     (paymentRequestEditViewController:didSelectField:)]) {
+    [_delegate paymentRequestEditViewController:self didSelectField:field];
+  }
 }
 
 #pragma mark MDCCollectionViewStylingDelegate
 
 - (CGFloat)collectionView:(UICollectionView*)collectionView
     cellHeightAtIndexPath:(NSIndexPath*)indexPath {
   CollectionViewItem* item =
       [self.collectionViewModel itemAtIndexPath:indexPath];
   switch (item.type) {
     case ItemTypeHeader:
@@ skipping 172 matching lines @@
   [_currentEditingCell.textField resignFirstResponder];
 
   if (![self validateForm])
     return;
 
   [self.delegate paymentRequestEditViewController:self
                            didFinishEditingFields:self.fields];
 }
 
 @end