C++11 override style change for athena

athena/system/shutdown_dialog.cc

 // Copyright 2014 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 "athena/system/shutdown_dialog.h"
 
 #include "athena/screen/public/screen_manager.h"
 #include "athena/strings/grit/athena_strings.h"
 #include "chromeos/dbus/dbus_thread_manager.h"
 #include "chromeos/dbus/power_manager_client.h"
@@ skipping 10 matching lines @@
 namespace {
 
 // The amount of time that the power button must be held to shut down the
 // device after shutdown dialog is shown.
 const int kShutdownTimeoutMs = 4000;
 
 class ModalWidgetDelegate : public views::WidgetDelegate {
  public:
   explicit ModalWidgetDelegate(views::View* contents_view)
       : contents_view_(contents_view) {}
-  virtual ~ModalWidgetDelegate() {}
+  ~ModalWidgetDelegate() override {}
 
   // Overridden from WidgetDelegate:
   virtual views::Widget* GetWidget() override {
     return contents_view_->GetWidget();
   }
   virtual const views::Widget* GetWidget() const override {
     return contents_view_->GetWidget();
   }
   virtual views::View* GetContentsView() override { return contents_view_; }
   virtual ui::ModalType GetModalType() const override {
@@ skipping 78 matching lines @@
             ->RequestSuspend();
       }
       state_ = STATE_OTHER;
       timer_.Stop();
       shutdown_warning_message_.reset();
       break;
   }
 }
 
 }  // namespace athena