Add a couple of notifications related settings to app/extensions sync:

chrome/browser/extensions/extension_service.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_BROWSER_EXTENSIONS_EXTENSION_SERVICE_H_
 #define CHROME_BROWSER_EXTENSIONS_EXTENSION_SERVICE_H_
 #pragma once
 
 #include <map>
 #include <set>
@@ skipping 193 matching lines @@
 
   const FilePath& install_directory() const { return install_directory_; }
 
   AppsPromo* apps_promo() { return &apps_promo_; }
 
   // Whether this extension can run in an incognito window.
   virtual bool IsIncognitoEnabled(const std::string& extension_id) const;
   virtual void SetIsIncognitoEnabled(const std::string& extension_id,
                                      bool enabled);
 
+  virtual void SetAppNotificationSetupDone(const std::string& extension_id,
+      bool value);
+
+  virtual void SetAppNotificationDisabled(const std::string& extension_id,
+      bool value);
+
   // Returns true if the given extension can see events and data from another
   // sub-profile (incognito to original profile, or vice versa).
   bool CanCrossIncognito(const Extension* extension);
 
   // Returns true if the given extension can be loaded in incognito.
   bool CanLoadInIncognito(const Extension* extension) const;
 
   // Whether this extension can inject scripts into pages with file URLs.
   bool AllowFileAccess(const Extension* extension);
   // Will reload the extension since this permission is applied at loading time
@@ skipping 615 matching lines @@
   ExtensionWarningSet extension_warnings_;
 
   FRIEND_TEST_ALL_PREFIXES(ExtensionServiceTest,
                            InstallAppsWithUnlimtedStorage);
   FRIEND_TEST_ALL_PREFIXES(ExtensionServiceTest,
                            InstallAppsAndCheckStorageProtection);
   DISALLOW_COPY_AND_ASSIGN(ExtensionService);
 };
 
 #endif  // CHROME_BROWSER_EXTENSIONS_EXTENSION_SERVICE_H_