Add LogoutConfirmationController to show LogoutConfirmationDialogs

ash/shell.cc

Index: ash/shell.cc
diff --git a/ash/shell.cc b/ash/shell.cc
index b46ad3fa838445465eced9b8b6ff84539c0ee001..2b6a8c9998837261d66b1acea76f61252ed4a3d1 100644
--- a/ash/shell.cc
+++ b/ash/shell.cc
@@ -49,6 +49,7 @@
 #include "ash/shell_factory.h"
 #include "ash/shell_window_ids.h"
 #include "ash/system/locale/locale_notification_controller.h"
+#include "ash/system/session/logout_confirmation_controller.h"
 #include "ash/system/status_area_widget.h"
 #include "ash/system/tray/system_tray_delegate.h"
 #include "ash/system/tray/system_tray_notifier.h"
@@ -80,6 +81,7 @@
 #include "ash/wm/window_util.h"
 #include "ash/wm/workspace_controller.h"
 #include "base/bind.h"
+#include "base/bind_helpers.h"
 #include "base/command_line.h"
 #include "base/debug/trace_event.h"
 #include "ui/aura/client/aura_constants.h"
@@ -666,6 +668,9 @@ Shell::~Shell() {
   // TODO(xiyuan): Move it back when app list container is no longer needed.
   app_list_controller_.reset();
 
+  // Destroy the LogoutConfirmationController before the SystemTrayDelegate.
+  logout_confirmation_controller_.reset();
+
   // Destroy SystemTrayDelegate before destroying the status area(s).
   system_tray_delegate_->Shutdown();
   system_tray_delegate_.reset();
@@ -969,6 +974,12 @@ void Shell::Init() {
   // Initialize system_tray_delegate_ after StatusAreaWidget is created.
   system_tray_delegate_->Initialize();
 
+  // Create the LogoutConfirmationController after the SystemTrayDelegate.
+  logout_confirmation_controller_.reset(
+      new internal::LogoutConfirmationController(
+          base::Bind(&SystemTrayDelegate::SignOut,
+                     base::Unretained(system_tray_delegate_.get()))));
+
   // TODO(oshima): Initialize all RootWindowControllers once, and
   // initialize controller/delegates above when initializing the
   // primary root window controller.