PaymentApp: Implement respondWith() in PaymentRequestEvent. (blink side)

third_party/WebKit/public/platform/modules/payments/WebPaymentAppResponse.h

Index: third_party/WebKit/public/platform/modules/payments/WebPaymentAppResponse.h
diff --git a/third_party/WebKit/public/platform/modules/payments/WebPaymentAppResponse.h b/third_party/WebKit/public/platform/modules/payments/WebPaymentAppResponse.h
new file mode 100644
index 0000000000000000000000000000000000000000..51ab72cdedafedcc7a441f71aab2b985f642259f
--- /dev/null
+++ b/third_party/WebKit/public/platform/modules/payments/WebPaymentAppResponse.h
@@ -0,0 +1,20 @@
+// 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 WebPaymentAppResponse_h
+#define WebPaymentAppResponse_h
+
+#include "public/platform/WebString.h"
+
+namespace blink {
+
+// https://w3c.github.io/webpayments-payment-apps-api/#idl-def-paymentappresponse
+struct WebPaymentAppResponse {
+  WebString methodName;
+  WebString stringifiedDetails;
+};
+
+}  // namespace blink
+
+#endif  // WebPaymentAppResponse_h