Add a SigninAllowed policy.

chrome/browser/ui/browser_command_controller.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_BROWSER_COMMAND_CONTROLLER_H_
 #define CHROME_BROWSER_UI_BROWSER_COMMAND_CONTROLLER_H_
 
 #include "base/prefs/public/pref_change_registrar.h"
-#include "chrome/browser/api/sync/profile_sync_service_observer.h"
+#include "base/prefs/public/pref_member.h"
 #include "chrome/browser/command_updater.h"
 #include "chrome/browser/command_updater_delegate.h"
 #include "chrome/browser/profiles/profile_info_cache_observer.h"
 #include "chrome/browser/sessions/tab_restore_service_observer.h"
 #include "chrome/browser/ui/tabs/tab_strip_model_observer.h"
 #include "content/public/browser/notification_observer.h"
 #include "content/public/browser/notification_registrar.h"
 #include "ui/base/window_open_disposition.h"
 
 class Browser;
@@ skipping 142 matching lines @@
   // window is in.
   void UpdateCommandsForFullscreenMode(FullScreenMode fullscreen_mode);
 
   // Update commands whose state depends on whether multiple profiles are
   // allowed.
   void UpdateCommandsForMultipleProfiles();
 
   // Updates the printing command state.
   void UpdatePrintingState();
 
+  // Updates the SHOW_SYNC_SETUP menu entry.
+  void OnSigninAllowedPrefChange();
+
   // Updates the save-page-as command state.
   void UpdateSaveAsState();
 
+  // Updates the show-sync command state.
+  void UpdateShowSyncState(bool show_main_ui);
+
   // Ask the Reload/Stop button to change its icon, and update the Stop command
   // state.  |is_loading| is true if the current WebContents is loading.
   // |force| is true if the button should change its icon immediately.
   void UpdateReloadStopState(bool is_loading, bool force);
 
   // Updates commands for find.
   void UpdateCommandsForFind();
 
   // Add/remove observers for interstitial attachment/detachment from
   // |contents|.
@@ skipping 15 matching lines @@
 
   // Stores the last blocked command id when |block_command_execution_| is true.
   int last_blocked_command_id_;
 
   // Stores the disposition type of the last blocked command.
   WindowOpenDisposition last_blocked_command_disposition_;
 
   content::NotificationRegistrar registrar_;
   PrefChangeRegistrar profile_pref_registrar_;
   PrefChangeRegistrar local_pref_registrar_;
+  BooleanPrefMember pref_signin_allowed_;
 
   DISALLOW_COPY_AND_ASSIGN(BrowserCommandController);
 };
 
 }  // namespace chrome
 
 #endif  // CHROME_BROWSER_UI_BROWSER_COMMAND_CONTROLLER_H_