[Payments] Improve the closing of the PR dialog.

components/payments/payment_request_dialog.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 COMPONENTS_PAYMENTS_PAYMENT_REQUEST_DIALOG_H_
+#define COMPONENTS_PAYMENTS_PAYMENT_REQUEST_DIALOG_H_
+
+namespace payments {
+
+// Used to interact with a cross-platform Payment Request dialog.
+class PaymentRequestDialog {
+ public:
+  virtual ~PaymentRequestDialog() {}
+
+  virtual void ShowDialog() = 0;
+
+  // |propagate_to_renderer| indicates whether to warn the renderer of the
+  // dialog closure. Therefore, if the dialog is being closed as a result of a
+  // renderer event, |propagate_to_renderer| should be false (the renderer is
+  // aware). On the other hand if the dialog is closed due to a user gesture,
+  // the renderer needs to know.
+  virtual void CloseDialog(bool propagate_to_renderer) = 0;
+};
+
+}  // namespace payments
+
+#endif  // COMPONENTS_PAYMENTS_PAYMENT_REQUEST_DIALOG_H_