[Payment Request] Payment request summary view pending state

ios/chrome/browser/payments/payment_method_selection_coordinator.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_coordinator.h"
 
 #include "components/autofill/core/browser/credit_card.h"
 #include "ios/chrome/browser/payments/payment_request.h"
 
 #if !defined(__has_feature) || !__has_feature(objc_arc)
@@ skipping 49 matching lines @@
   [_delegate paymentMethodSelectionCoordinatorDidReturn:self];
 }
 
 - (void)delayedNotifyDelegateOfSelection:(autofill::CreditCard*)paymentMethod {
   _viewController.view.userInteractionEnabled = NO;
   __weak PaymentMethodSelectionCoordinator* weakSelf = self;
   dispatch_after(dispatch_time(DISPATCH_TIME_NOW,
                                static_cast<int64_t>(0.2 * NSEC_PER_SEC)),
                  dispatch_get_main_queue(), ^{
                    PaymentMethodSelectionCoordinator* strongSelf = weakSelf;
+                   // Early return if the coordinator has been deallocated.
+                   if (!strongSelf)
+                     return;
+
                    strongSelf.viewController.view.userInteractionEnabled = YES;
                    [strongSelf.delegate
                        paymentMethodSelectionCoordinator:strongSelf
                                   didSelectPaymentMethod:paymentMethod];
                  });
 }
 
 @end