Add a SigninAllowed policy.

chrome/browser/ui/webui/options/browser_options_handler.h

 // Copyright (c) 2012 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_UI_WEBUI_OPTIONS_BROWSER_OPTIONS_HANDLER_H_
 #define CHROME_BROWSER_UI_WEBUI_OPTIONS_BROWSER_OPTIONS_HANDLER_H_
 
 #include "base/memory/ref_counted.h"
 #include "base/memory/scoped_ptr.h"
 #include "base/memory/weak_ptr.h"
@@ skipping 38 matching lines @@
   // OptionsPageUIHandler implementation.
   virtual void GetLocalizedValues(DictionaryValue* values) OVERRIDE;
   virtual void PageLoadStarted() OVERRIDE;
   virtual void InitializeHandler() OVERRIDE;
   virtual void InitializePage() OVERRIDE;
   virtual void RegisterMessages() OVERRIDE;
 
   // ProfileSyncServiceObserver implementation.
   virtual void OnStateChanged() OVERRIDE;
 
+  // Will be called when the kSigninAllowed pref has changed.
+  void OnSigninAllowedPrefChange();
+
   // ShellIntegration::DefaultWebClientObserver implementation.
   virtual void SetDefaultWebClientUIState(
       ShellIntegration::DefaultWebClientUIState state) OVERRIDE;
   virtual bool IsInteractiveSetDefaultPermitted() OVERRIDE;
 
   // TemplateURLServiceObserver implementation.
   virtual void OnTemplateURLServiceChanged() OVERRIDE;
 
   // Create a Windows' profile specific desktop shortcut.
   static void CreateDesktopShortcutForProfile(
@@ skipping 212 matching lines @@
   StringPrefMember cloud_print_connector_email_;
   BooleanPrefMember cloud_print_connector_enabled_;
   bool cloud_print_connector_ui_enabled_;
   scoped_ptr<CloudPrintSetupHandler> cloud_print_setup_handler_;
 #endif
 
   StringPrefMember auto_open_files_;
   IntegerPrefMember default_font_size_;
   DoublePrefMember default_zoom_level_;
 
-#if !defined(OS_CHROMEOS)
-  PrefChangeRegistrar proxy_prefs_;
-#endif  // !defined(OS_CHROMEOS)
+  PrefChangeRegistrar profile_pref_registrar_;
 
   DISALLOW_COPY_AND_ASSIGN(BrowserOptionsHandler);
 };
 
 }  // namespace options
 
 #endif  // CHROME_BROWSER_UI_WEBUI_OPTIONS_BROWSER_OPTIONS_HANDLER_H_