Implement the ServiceWorkerRegistration.showNotification() method.

Source/modules/notifications/ServiceWorkerRegistrationNotifications.h

Index: Source/modules/notifications/ServiceWorkerRegistrationNotifications.h
diff --git a/Source/modules/notifications/ServiceWorkerRegistrationNotifications.h b/Source/modules/notifications/ServiceWorkerRegistrationNotifications.h
new file mode 100644
index 0000000000000000000000000000000000000000..688fd3d1a424b055bef960bc88ed928d4a4df32f
--- /dev/null
+++ b/Source/modules/notifications/ServiceWorkerRegistrationNotifications.h
@@ -0,0 +1,23 @@
+// Copyright 2014 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 ServiceWorkerRegistrationNotifications_h
+#define ServiceWorkerRegistrationNotifications_h
+
+#include "bindings/core/v8/ScriptPromise.h"
+#include "modules/serviceworkers/ServiceWorkerRegistration.h"
+
+namespace blink {
+
+class NotificationOptions;
+class ScriptState;
+
+class ServiceWorkerRegistrationNotifications {
+public:
+    static ScriptPromise showNotification(ScriptState*, ServiceWorkerRegistration&, const String& title, const NotificationOptions&);
+};
+
+} // namespace blink
+
+#endif // ServiceWorkerRegistrationNotifications_h