This will cause build failed since a include file does not exist.

chrome/common/chrome_notification_types.h

 // Copyright (c) 2011 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_CHROME_NOTIFICATION_TYPES_H_
 #define CHROME_COMMON_CHROME_NOTIFICATION_TYPES_H_
 #pragma once
 
 #include "content/common/content_notification_types.h"
 
@@ skipping 301 matching lines @@
   NOTIFICATION_URLS_STARRED,
 
   // Sent when the bookmark bar model finishes loading. This source is the
   // Profile, and the details aren't used.
   NOTIFICATION_BOOKMARK_MODEL_LOADED,
 
   // Sent when the bookmark bubble is shown for a particular URL. The source
   // is the profile, the details the URL.
   NOTIFICATION_BOOKMARK_BUBBLE_SHOWN,
 
-  // Task Manager ------------------------------------------------------------
-
-  // Sent when WebUI TaskManager opens and is ready for showing tasks.
-  NOTIFICATION_TASK_MANAGER_WINDOW_READY,
-
   // Non-history storage services --------------------------------------------
 
   // Notification that the TemplateURLService has finished loading from the
   // database. The source is the TemplateURLService, and the details are
   // NoDetails.
   NOTIFICATION_TEMPLATE_URL_SERVICE_LOADED,
 
   // Sent when a TemplateURL is removed from the model. The source is the
   // Profile, and the details the id of the TemplateURL being removed.
   NOTIFICATION_TEMPLATE_URL_REMOVED,
@@ skipping 604 matching lines @@
   // Currently only Content and Chrome define and use notifications.
   // Custom notifications not belonging to Content and Chrome should start
   // from here.
   NOTIFICATION_CHROME_END,
 };
 
 }  // namespace chrome
 
 
 #endif  // CHROME_COMMON_CHROME_NOTIFICATION_TYPES_H_