Make the kiosk code not depend on Ash in Athena

chrome/browser/chromeos/app_mode/kiosk_app_manager.h

Index: chrome/browser/chromeos/app_mode/kiosk_app_manager.h
diff --git a/chrome/browser/chromeos/app_mode/kiosk_app_manager.h b/chrome/browser/chromeos/app_mode/kiosk_app_manager.h
index 78a6cb5f90bd754446bbd8901909332d138c3e45..a1006b822d11784dca416b106a2994b3ff0d46f3 100644
--- a/chrome/browser/chromeos/app_mode/kiosk_app_manager.h
+++ b/chrome/browser/chromeos/app_mode/kiosk_app_manager.h
@@ -37,7 +37,10 @@ namespace chromeos {
 class KioskAppData;
 class KioskAppExternalLoader;
 class KioskAppManagerObserver;
+
+#if !defined(USE_ATHENA)
 class KioskExternalUpdater;
+#endif
 
 // KioskAppManager manages cached app data.
 class KioskAppManager : public KioskAppDataDelegate,
@@ -274,7 +277,10 @@ class KioskAppManager : public KioskAppDataDelegate,
       local_account_auto_login_id_subscription_;
 
   scoped_ptr<ExternalCache> external_cache_;
+
+#if !defined(USE_ATHENA)
   scoped_ptr<KioskExternalUpdater> usb_stick_updater_;
+#endif
 
   // The extension external loader for installing kiosk app.
   bool external_loader_created_;