Remove self as delegate when cleaning up AppLaunchController.

chrome/browser/chromeos/login/app_launch_controller.cc

 // Copyright 2013 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/chromeos/login/app_launch_controller.h"
 
 #include "base/files/file_path.h"
 #include "base/json/json_file_value_serializer.h"
 #include "base/time/time.h"
 #include "base/values.h"
@@ skipping 33 matching lines @@
       oobe_display_(oobe_display),
       app_launch_splash_screen_actor_(
           oobe_display_->GetAppLaunchSplashScreenActor()),
       error_screen_actor_(oobe_display_->GetErrorScreenActor()),
       waiting_for_network_(false),
       showing_network_dialog_(false),
       launch_splash_start_time_(0) {
 }
 
 AppLaunchController::~AppLaunchController() {
+  app_launch_splash_screen_actor_->SetDelegate(NULL);
 }
 
 void AppLaunchController::StartAppLaunch() {
   DVLOG(1) << "Starting kiosk mode...";
   launch_splash_start_time_ = base::TimeTicks::Now().ToInternalValue();
 
   // TODO(tengs): Add a loading profile app launch state.
   app_launch_splash_screen_actor_->SetDelegate(this);
   app_launch_splash_screen_actor_->Show(app_id_);
 
@@ skipping 136 matching lines @@
   LOG(ERROR) << "Kiosk launch failed. Will now shut down.";
   DCHECK_NE(KioskAppLaunchError::NONE, error);
 
   // Saves the error and ends the session to go back to login screen.
   KioskAppLaunchError::Save(error);
   chrome::AttemptUserExit();
   Cleanup();
 }
 
 }   // namespace chromeos