Remove NOTIFICATION_EXTENSION_ENABLED.

extensions/browser/notification_types.h

 // 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 EXTENSIONS_BROWSER_NOTIFICATION_TYPES_H_
 #define EXTENSIONS_BROWSER_NOTIFICATION_TYPES_H_
 
 #include <string>
 
 #include "content/public/browser/notification_types.h"
@@ skipping 20 matching lines @@
   // testing scenarios this can happen multiple times if extensions are
   // unloaded and reloaded. The source is a BrowserContext*.
   //
   // DEPRECATED: Use ExtensionSystem::Get(browser_context)->ready().Post().
   NOTIFICATION_EXTENSIONS_READY_DEPRECATED,
 
   // An error occured while attempting to load an extension. The details are a
   // string with details about why the load failed.
   NOTIFICATION_EXTENSION_LOAD_ERROR,
 
-  // Sent when an extension is enabled. Under most circumstances, listeners will
-  // want to use ExtensionRegistryObserver::OnExtensionLoaded(). This
-  // notification is only fired when the "Enable" button is hit in the
-  // extensions tab. The details are an Extension, and the source is a
-  // BrowserContext*.
-  NOTIFICATION_EXTENSION_ENABLED,
-
   // Sent when attempting to load a new extension, but they are disabled. The
   // details are an Extension, and the source is a BrowserContext*.
   NOTIFICATION_EXTENSION_UPDATE_DISABLED,
 
   // Sent when an extension's permissions change. The details are an
   // UpdatedExtensionPermissionsInfo, and the source is a BrowserContext*.
   NOTIFICATION_EXTENSION_PERMISSIONS_UPDATED,
 
   // An error occured during extension install. The details are a string with
   // details about why the install failed.
@@ skipping 121 matching lines @@
                                  const std::string& accelerator);
 
   std::string extension_id;
   std::string command_name;
   std::string accelerator;
 };
 
 }  // namespace extensions
 
 #endif  // EXTENSIONS_BROWSER_NOTIFICATION_TYPES_H_