Push API: define push event on Service Worker.

Source/modules/push_messaging/ServiceWorkerGlobalScopePush.h

Index: Source/modules/push_messaging/ServiceWorkerGlobalScopePush.h
diff --git a/Source/modules/push_messaging/ServiceWorkerGlobalScopePush.h b/Source/modules/push_messaging/ServiceWorkerGlobalScopePush.h
new file mode 100644
index 0000000000000000000000000000000000000000..4c92682f076c75a84643c1a8470b539e1681f33e
--- /dev/null
+++ b/Source/modules/push_messaging/ServiceWorkerGlobalScopePush.h
@@ -0,0 +1,19 @@
+// 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 ServiceWorkerGlobalScopePush_h
+#define ServiceWorkerGlobalScopePush_h
+
+#include "core/events/EventTarget.h"
+
+namespace WebCore {
+
+class ServiceWorkerGlobalScopePush {
+public:
+    DEFINE_STATIC_ATTRIBUTE_EVENT_LISTENER(push);
+};
+
+} // namespace WebCore
+
+#endif // ServiceWorkerGlobalScopePush_h