[Payment Request] Error message screen

ios/chrome/browser/payments/payment_method_selection_view_controller.mm

Index: ios/chrome/browser/payments/payment_method_selection_view_controller.mm
diff --git a/ios/chrome/browser/payments/payment_method_selection_view_controller.mm b/ios/chrome/browser/payments/payment_method_selection_view_controller.mm
index 2ab51c94e663d0774bfd1011dec0c76b82f5df0a..bf3f9d330b38fa3d6d5bec10ead72f28df6bda5d 100644
--- a/ios/chrome/browser/payments/payment_method_selection_view_controller.mm
+++ b/ios/chrome/browser/payments/payment_method_selection_view_controller.mm
@@ -13,6 +13,7 @@
 #include "components/strings/grit/components_strings.h"
 #import "ios/chrome/browser/payments/cells/payment_method_item.h"
 #import "ios/chrome/browser/payments/cells/payments_text_item.h"
+#import "ios/chrome/browser/payments/payment_method_selection_view_controller_actions.h"
 #include "ios/chrome/browser/payments/payment_request.h"
 #import "ios/chrome/browser/ui/collection_view/cells/MDCCollectionViewCell+Chrome.h"
 #import "ios/chrome/browser/ui/collection_view/cells/collection_view_detail_item.h"
@@ -27,8 +28,8 @@
 #include "ui/base/l10n/l10n_util.h"
 #include "ui/base/resource/resource_bundle.h"
 
-NSString* const kPaymentMethodSelectionCollectionViewId =
-    @"kPaymentMethodSelectionCollectionViewId";
+NSString* const kPaymentMethodSelectionCollectionViewID =
+    @"kPaymentMethodSelectionCollectionViewID";
 
 namespace {
 
@@ -45,7 +46,8 @@ typedef NS_ENUM(NSInteger, ItemType) {
 
 }  // namespace
 
-@interface PaymentMethodSelectionViewController () {
+@interface PaymentMethodSelectionViewController ()<
+    PaymentMethodSelectionViewControllerActions> {
   base::WeakNSProtocol<id<PaymentMethodSelectionViewControllerDelegate>>
       _delegate;
 
@@ -58,9 +60,6 @@ typedef NS_ENUM(NSInteger, ItemType) {
   PaymentMethodItem* _selectedItem;
 }
 
-// Called when the user presses the return button.
-- (void)onReturn;
-
 @end
 
 @implementation PaymentMethodSelectionViewController
@@ -71,6 +70,7 @@ typedef NS_ENUM(NSInteger, ItemType) {
     [self setTitle:l10n_util::GetNSString(
                        IDS_IOS_PAYMENT_REQUEST_METHOD_SELECTION_TITLE)];
 
+    // Set up leading (return) button.
     UIBarButtonItem* returnButton =
         [ChromeIcon templateBarButtonItemWithImage:[ChromeIcon backIcon]
                                             target:nil
@@ -138,7 +138,7 @@ typedef NS_ENUM(NSInteger, ItemType) {
 - (void)viewDidLoad {
   [super viewDidLoad];
   self.collectionView.accessibilityIdentifier =
-      kPaymentMethodSelectionCollectionViewId;
+      kPaymentMethodSelectionCollectionViewID;
 
   // Customize collection view settings.
   self.styler.cellStyle = MDCCollectionViewCellStyleCard;