PaymentApp: Add interfaces for PaymentRequestEvent.

third_party/WebKit/Source/modules/payments/PaymentRequestEvent.cpp

+// 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.
+
+#include "modules/payments/PaymentRequestEvent.h"
+
+#include "wtf/text/AtomicString.h"
+
+namespace blink {
+
+const AtomicString& PaymentRequestEvent::interfaceName() const {
+  return EventNames::PaymentRequestEvent;
+}
+
+void PaymentRequestEvent::data(PaymentAppRequestData& data) const {
+  NOTIMPLEMENTED();
+}
+
+void PaymentRequestEvent::respondWith(ScriptPromise) {
+  NOTIMPLEMENTED();
+}
+
+DEFINE_TRACE(PaymentRequestEvent) {
+  ExtendableEvent::trace(visitor);
+}
+
+PaymentRequestEvent::PaymentRequestEvent(const AtomicString& type,
+                                         const PaymentAppRequestData& data,
+                                         WaitUntilObserver* observer)
+    : ExtendableEvent(type, ExtendableEventInit(), observer) {}
+
+}  // namespace blink