[Payment Request] Error message screen

ios/chrome/browser/payments/payment_request_error_view_controller.h

+// 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.
+
+#ifndef IOS_CHROME_BROWSER_PAYMENTS_PAYMENT_REQUEST_ERROR_VIEW_CONTROLLER_H_
+#define IOS_CHROME_BROWSER_PAYMENTS_PAYMENT_REQUEST_ERROR_VIEW_CONTROLLER_H_
+
+#import <UIKit/UIKit.h>
+
+#import "ios/chrome/browser/ui/collection_view/collection_view_controller.h"
+
+extern NSString* const kPaymentRequestErrorCollectionViewID;
+
+@class PaymentRequestErrorViewController;
+
+// Delegate protocol for PaymentRequestErrorViewController.
+@protocol PaymentRequestErrorViewControllerDelegate<NSObject>
+
+// Notifies the delegate that the user has dismissed the error.
+- (void)paymentRequestErrorViewControllerDidDismiss:
+    (PaymentRequestErrorViewController*)controller;
+
+@end
+
+// View controller responsible for presenting the error for the payment request.
+@interface PaymentRequestErrorViewController : CollectionViewController
+
+// The error message to display, if any.
+@property(nonatomic, copy) NSString* errorMessage;
+
+// The delegate to be notified when the user dismisses the error.
+@property(nonatomic, weak)
+    id<PaymentRequestErrorViewControllerDelegate> delegate;
+
+- (instancetype)init NS_DESIGNATED_INITIALIZER;
+
+- (instancetype)initWithStyle:(CollectionViewControllerStyle)style
+    NS_UNAVAILABLE;
+
+@end
+
+#endif  // IOS_CHROME_BROWSER_PAYMENTS_PAYMENT_REQUEST_ERROR_VIEW_CONTROLLER_H_