diff -r 000000000000 -r 6474c204b198 ipc/chromium/src/chrome/common/notification_observer.h
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/ipc/chromium/src/chrome/common/notification_observer.h	Wed Dec 31 06:09:35 2014 +0100
@@ -0,0 +1,23 @@
+// Copyright (c) 2009 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 CHROME_COMMON_NOTIFICATION_OBSERVER_H_
+#define CHROME_COMMON_NOTIFICATION_OBSERVER_H_
+
+class NotificationDetails;
+class NotificationSource;
+class NotificationType;
+
+// This is the base class for notification observers. When a matching
+// notification is posted to the notification service, Observe is called.
+class NotificationObserver {
+ public:
+  virtual ~NotificationObserver();
+
+  virtual void Observe(NotificationType type,
+                       const NotificationSource& source,
+                       const NotificationDetails& details) = 0;
+};
+
+#endif  // CHROME_COMMON_NOTIFICATION_OBSERVER_H_