Update {virtual,override,final} to follow C++11 style in ash.

ash/system/chromeos/session/logout_confirmation_controller_unittest.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 "ash/system/chromeos/session/logout_confirmation_controller.h"
 
 #include "base/bind.h"
 #include "base/bind_helpers.h"
 #include "base/memory/ref_counted.h"
 #include "base/test/test_mock_time_task_runner.h"
 #include "base/thread_task_runner_handle.h"
 #include "testing/gtest/include/gtest/gtest.h"
 
 namespace ash {
 
 class LogoutConfirmationControllerTest : public testing::Test {
  protected:
   LogoutConfirmationControllerTest();
-  virtual ~LogoutConfirmationControllerTest();
+  ~LogoutConfirmationControllerTest() override;
 
   void LogOut();
 
   bool log_out_called_;
 
   scoped_refptr<base::TestMockTimeTaskRunner> runner_;
   base::ThreadTaskRunnerHandle runner_handle_;
 
   LogoutConfirmationController controller_;
 
@@ skipping 115 matching lines @@
   controller_.ConfirmLogout(
       runner_->GetCurrentMockTime() + base::TimeDelta::FromSeconds(10));
   EXPECT_FALSE(log_out_called_);
   runner_->FastForwardBy(base::TimeDelta::FromSeconds(9));
   EXPECT_FALSE(log_out_called_);
   runner_->FastForwardBy(base::TimeDelta::FromSeconds(2));
   EXPECT_TRUE(log_out_called_);
 }
 
 }  // namespace ash