Standardize usage of virtual/override/final specifiers.

ash/wm/mru_window_tracker_unittest.cc

 // Copyright 2013 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/shell.h"
 #include "ash/test/ash_test_base.h"
 #include "ash/test/test_shelf_delegate.h"
 #include "ash/wm/mru_window_tracker.h"
 #include "ash/wm/window_state.h"
 #include "ash/wm/window_util.h"
 #include "base/compiler_specific.h"
 #include "ui/aura/test/test_window_delegate.h"
 #include "ui/aura/window.h"
 #include "ui/views/widget/widget.h"
 
 namespace ash {
 
 class MruWindowTrackerTest : public test::AshTestBase {
  public:
   MruWindowTrackerTest() {}
-  virtual ~MruWindowTrackerTest() {}
+  ~MruWindowTrackerTest() override {}
 
   aura::Window* CreateWindow() {
     return CreateTestWindowInShellWithBounds(gfx::Rect(0, 0, 400, 400));
   }
 
   ash::MruWindowTracker* mru_window_tracker() {
     return Shell::GetInstance()->mru_window_tracker();
   }
 
  private:
@@ skipping 42 matching lines @@
       mru_window_tracker()->BuildMruWindowList();
   EXPECT_EQ(w2.get(), window_list[0]);
   EXPECT_EQ(w3.get(), window_list[1]);
   EXPECT_EQ(w6.get(), window_list[2]);
   EXPECT_EQ(w1.get(), window_list[3]);
   EXPECT_EQ(w4.get(), window_list[4]);
   EXPECT_EQ(w5.get(), window_list[5]);
 }
 
 }  // namespace ash