C++11 override style change for athena

athena/env/athena_env_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 "athena/env/public/athena_env.h"
 
 #include "athena/test/base/athena_test_base.h"
 #include "base/bind.h"
 #include "ui/gfx/display.h"
 #include "ui/gfx/screen.h"
@@ skipping 90 matching lines @@
   env->OnTerminating();
   env->RemoveTerminatingCallback(cb_1_2);
   env->RemoveTerminatingCallback(cb_2_1);
 }
 
 namespace {
 
 class AthenaShutdownTest : public test::AthenaTestBase {
  public:
   AthenaShutdownTest() {}
-  virtual ~AthenaShutdownTest() {}
+  ~AthenaShutdownTest() override {}
 
   virtual void TearDown() {
     test::AthenaTestBase::TearDown();
     ASSERT_NE(
         gfx::Display::kInvalidDisplayID,
         gfx::Screen::GetNativeScreen()->GetPrimaryDisplay().id());
   }
 
  private:
   DISALLOW_COPY_AND_ASSIGN(AthenaShutdownTest);
 };
 
 }  // namespace
 
 // gfx::Screen should be accessible after shutdown.
 TEST_F(AthenaShutdownTest, Shutdown) {
 }
 
 }  // namespace athena