Delete "shutdown without closing browsers" path

chrome/browser/ui/ash/chrome_shell_delegate_chromeos.cc

Index: chrome/browser/ui/ash/chrome_shell_delegate_chromeos.cc
diff --git a/chrome/browser/ui/ash/chrome_shell_delegate_chromeos.cc b/chrome/browser/ui/ash/chrome_shell_delegate_chromeos.cc
index 39ba0d31c3fd30803a780476aaadf1def9821eea..3b7864f24cf071d4bd9dd1977891f157cfcd6238 100644
--- a/chrome/browser/ui/ash/chrome_shell_delegate_chromeos.cc
+++ b/chrome/browser/ui/ash/chrome_shell_delegate_chromeos.cc
@@ -237,10 +237,8 @@ void ChromeShellDelegate::PreInit() {
       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() {
@@ -285,11 +283,6 @@ void ChromeShellDelegate::Observe(int type,
       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;
   }
@@ -302,7 +295,4 @@ void ChromeShellDelegate::PlatformInit() {
   registrar_.Add(this,
                  chrome::NOTIFICATION_SESSION_STARTED,
                  content::NotificationService::AllSources());
-  registrar_.Add(this,
-                 chrome::NOTIFICATION_APP_TERMINATING,
-                 content::NotificationService::AllSources());
 }