Delete "shutdown without closing browsers" path

chrome/browser/ui/ash/chrome_shell_delegate_chromeos.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/ui/ash/chrome_shell_delegate.h"
 
 #include "ash/accelerators/magnifier_key_scroller.h"
 #include "ash/accelerators/spoken_feedback_toggler.h"
 #include "ash/accessibility_delegate.h"
 #include "ash/media_delegate.h"
@@ skipping 219 matching lines @@
 }
 
 void ChromeShellDelegate::PreInit() {
   chromeos::LoadDisplayPreferences(IsFirstRunAfterBoot());
   // Set the observer now so that we can save the initial state
   // in Shell::Init.
   display_configuration_observer_.reset(
       new chromeos::DisplayConfigurationObserver());
 }
 
-void ChromeShellDelegate::Shutdown() {
-  content::RecordAction(base::UserMetricsAction("Shutdown"));
-  chromeos::DBusThreadManager::Get()->GetPowerManagerClient()->
-      RequestShutdown();
+void ChromeShellDelegate::PreShutdown() {
+  display_configuration_observer_.reset();
 }
 
 ash::SessionStateDelegate* ChromeShellDelegate::CreateSessionStateDelegate() {
   return new SessionStateDelegateChromeos;
 }
 
 ash::AccessibilityDelegate* ChromeShellDelegate::CreateAccessibilityDelegate() {
   return new AccessibilityDelegateImpl;
 }
 
@@ skipping 24 matching lines @@
         // Start the error notifier service to show auth notifications.
         SigninErrorNotifierFactory::GetForProfile(profile);
       }
       ash::Shell::GetInstance()->OnLoginUserProfilePrepared();
       break;
     }
     case chrome::NOTIFICATION_SESSION_STARTED:
       InitAfterSessionStart();
       ash::Shell::GetInstance()->ShowShelf();
       break;
-    case chrome::NOTIFICATION_APP_TERMINATING:
-      // Let classes unregister themselves as observers of the
-      // ash::Shell singleton before the shell is destroyed.
-      display_configuration_observer_.reset();
-      break;
     default:
       NOTREACHED() << "Unexpected notification " << type;
   }
 }
 
 void ChromeShellDelegate::PlatformInit() {
   registrar_.Add(this,
                  chrome::NOTIFICATION_LOGIN_USER_PROFILE_PREPARED,
                  content::NotificationService::AllSources());
   registrar_.Add(this,
                  chrome::NOTIFICATION_SESSION_STARTED,
                  content::NotificationService::AllSources());
-  registrar_.Add(this,
-                 chrome::NOTIFICATION_APP_TERMINATING,
-                 content::NotificationService::AllSources());
 }