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"
 #include "base/prefs/public/pref_member.h"
 #include "chrome/browser/api/sync/profile_sync_service_observer.h"
 #include "chrome/browser/printing/cloud_print/cloud_print_setup_handler.h"
 #include "chrome/browser/profiles/profile.h"
 #include "chrome/browser/search_engines/template_url_service_observer.h"
 #include "chrome/browser/shell_integration.h"
+#include "chrome/browser/signin/signin_pref_observer.h"
 #include "chrome/browser/ui/webui/options/options_ui.h"
 #include "ui/base/models/table_model_observer.h"
 #include "ui/shell_dialogs/select_file_dialog.h"
 
 #if defined(OS_CHROMEOS)
 #include "chrome/browser/chromeos/system/pointer_device_observer.h"
 #else
 #include "base/prefs/public/pref_change_registrar.h"
 #endif  // defined(OS_CHROMEOS)
 
 class AutocompleteController;
 class CloudPrintSetupHandler;
 class CustomHomePagesTableModel;
 class TemplateURLService;
 
 namespace options {
 
 // Chrome browser options page UI handler.
 class BrowserOptionsHandler
     : public OptionsPageUIHandler,
       public CloudPrintSetupHandlerDelegate,
       public ProfileSyncServiceObserver,
+      public SigninPrefObserver,
       public ui::SelectFileDialog::Listener,
       public ShellIntegration::DefaultWebClientObserver,
 #if defined(OS_CHROMEOS)
       public chromeos::system::PointerDeviceObserver::Observer,
 #endif
       public TemplateURLServiceObserver {
  public:
   BrowserOptionsHandler();
   virtual ~BrowserOptionsHandler();
 
   // 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;
 
+  // SigninPrefObserver implementation.
+  virtual void OnSigninAllowedPrefChange(bool signin_allowed) OVERRIDE;
+
   // 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 222 matching lines @@
 #if !defined(OS_CHROMEOS)
   PrefChangeRegistrar proxy_prefs_;
 #endif  // !defined(OS_CHROMEOS)
 
   DISALLOW_COPY_AND_ASSIGN(BrowserOptionsHandler);
 };
 
 }  // namespace options
 
 #endif  // CHROME_BROWSER_UI_WEBUI_OPTIONS_BROWSER_OPTIONS_HANDLER_H_