Added more tests for IncognitoModeAvailability.

chrome/browser/ui/ash/launcher/launcher_context_menu.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/ash/launcher/launcher_context_menu.h"
 
 #include <string>
 
 #include "ash/desktop_background/user_wallpaper_delegate.h"
 #include "ash/root_window_controller.h"
@@ skipping 113 matching lines @@
         int index = 0;
         extension_items_->AppendExtensionItems(
             app_id, string16(), &index);
         AddSeparatorIfNecessary(ui::NORMAL_SEPARATOR);
       }
     }
   }
   // Don't show the auto-hide menu item while in immersive mode because the
   // launcher always auto-hides in this mode and it's confusing when the
   // preference appears not to apply.
-  if (!ash::GetRootWindowController(root_window_)->IsImmersiveMode()) {
+  ash::internal::RootWindowController* root_window_controller =
+      ash::GetRootWindowController(root_window_);
+  if (root_window_controller != NULL &&
+      !root_window_controller->IsImmersiveMode()) {
     AddCheckItemWithStringId(
         MENU_AUTO_HIDE, IDS_AURA_LAUNCHER_CONTEXT_MENU_AUTO_HIDE);
   }
   if (CommandLine::ForCurrentProcess()->HasSwitch(
           switches::kShowLauncherAlignmentMenu)) {
     AddSubMenuWithStringId(MENU_ALIGNMENT_MENU,
                            IDS_AURA_LAUNCHER_CONTEXT_MENU_POSITION,
                            &launcher_alignment_menu_);
   }
   AddItem(MENU_CHANGE_WALLPAPER,
@@ skipping 116 matching lines @@
       break;
     case MENU_CHANGE_WALLPAPER:
       ash::Shell::GetInstance()->user_wallpaper_delegate()->
           OpenSetWallpaperPage();
       break;
     default:
       extension_items_->ExecuteCommand(command_id, NULL,
                                        content::ContextMenuParams());
   }
 }