Added more tests for IncognitoModeAvailability.

chrome/browser/ui/ash/launcher/launcher_context_menu.cc

Index: chrome/browser/ui/ash/launcher/launcher_context_menu.cc
diff --git a/chrome/browser/ui/ash/launcher/launcher_context_menu.cc b/chrome/browser/ui/ash/launcher/launcher_context_menu.cc
index 9f28cb2e220e16c4cf0a5e2a06dcbec4a9c9c230..03543ac42e73f98db623230ee080d3e048eb33ba 100644
--- a/chrome/browser/ui/ash/launcher/launcher_context_menu.cc
+++ b/chrome/browser/ui/ash/launcher/launcher_context_menu.cc
@@ -131,7 +131,10 @@ void LauncherContextMenu::Init() {
   // 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);
   }