Disable the sign-in command when incognito mode is forced.

chrome/browser/ui/browser_command_controller.cc

 // 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.
 
 #include "chrome/browser/ui/browser_command_controller.h"
 
 #include "base/prefs/pref_service.h"
 #include "chrome/app/chrome_command_ids.h"
 #include "chrome/browser/browser_process.h"
 #include "chrome/browser/defaults.h"
@@ skipping 978 matching lines @@
       IDC_SHOW_BOOKMARK_MANAGER,
       browser_defaults::bookmarks_enabled && command_enabled);
   ExtensionService* extension_service = profile->GetExtensionService();
   bool enable_extensions =
       extension_service && extension_service->extensions_enabled();
   command_updater->UpdateCommandEnabled(IDC_MANAGE_EXTENSIONS,
                                         enable_extensions && command_enabled);
 
   command_updater->UpdateCommandEnabled(IDC_IMPORT_SETTINGS, command_enabled);
   command_updater->UpdateCommandEnabled(IDC_OPTIONS, command_enabled);
+  command_updater->UpdateCommandEnabled(IDC_SHOW_SIGNIN, command_enabled);
 }
 
 void BrowserCommandController::UpdateCommandsForIncognitoAvailability() {
   UpdateSharedCommandsForIncognitoAvailability(&command_updater_, profile());
 
   if (!IsShowingMainUI()) {
     command_updater_.UpdateCommandEnabled(IDC_IMPORT_SETTINGS, false);
     command_updater_.UpdateCommandEnabled(IDC_OPTIONS, false);
   }
 }
@@ skipping 251 matching lines @@
 
 BrowserWindow* BrowserCommandController::window() {
   return browser_->window();
 }
 
 Profile* BrowserCommandController::profile() {
   return browser_->profile();
 }
 
 }  // namespace chrome