[Payments] Improve the closing of the PR dialog.

components/payments/payment_request.h

 // 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.
 
 #ifndef COMPONENTS_PAYMENTS_PAYMENT_REQUEST_H_
 #define COMPONENTS_PAYMENTS_PAYMENT_REQUEST_H_
 
 #include <memory>
 #include <string>
 #include <vector>
@@ skipping 25 matching lines @@
       mojo::InterfaceRequest<payments::mojom::PaymentRequest> request);
   ~PaymentRequest() override;
 
   // payments::mojom::PaymentRequest "stub"
   void Init(payments::mojom::PaymentRequestClientPtr client,
             std::vector<payments::mojom::PaymentMethodDataPtr> methodData,
             payments::mojom::PaymentDetailsPtr details,
             payments::mojom::PaymentOptionsPtr options) override;
   void Show() override;
   void UpdateWith(payments::mojom::PaymentDetailsPtr details) override {}
-  void Abort() override {}
+  void Abort() override;
   void Complete(payments::mojom::PaymentComplete result) override {}
   void CanMakePayment() override {}
 
-  void Cancel();
-  void OnError();
+  // Called when the user explicitely cancelled the flow. Will send a message
+  // to the renderer which will indirectly destroy this object (through
+  // OnConnectionTerminated).
+  void UserCancelled();
+
+  // As a result of a browser-side error or renderer-initiated mojo channel
+  // closure (e.g. there was an error on the renderer side, or payment was
+  // successful), this method is called. It is responsible for cleaning up,
+  // such as possibly closing the dialog.
+  void OnConnectionTerminated();
 
   // Returns the CurrencyFormatter instance for this PaymentRequest.
   // |locale_name| should be the result of the browser's GetApplicationLocale().
   // Note: Having multiple currencies per PaymentRequest is not supported; hence
   // the CurrencyFormatter is cached here.
   CurrencyFormatter* GetOrCreateCurrencyFormatter(
       const std::string& currency_code,
       const base::Optional<std::string> currency_system,
       const std::string& locale_name);
 
@@ skipping 22 matching lines @@
   payments::mojom::PaymentDetailsPtr details_;
   std::unique_ptr<CurrencyFormatter> currency_formatter_;
   std::unique_ptr<autofill::AutofillProfile> profile_;
 
   DISALLOW_COPY_AND_ASSIGN(PaymentRequest);
 };
 
 }  // namespace payments
 
 #endif  // COMPONENTS_PAYMENTS_PAYMENT_REQUEST_H_