Standardize usage of virtual/override/final specifiers.

ash/shell/window_watcher.cc

 // Copyright (c) 2012 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/window_watcher.h"
 
 #include "ash/display/display_controller.h"
 #include "ash/shelf/shelf.h"
 #include "ash/shelf/shelf_item_delegate_manager.h"
 #include "ash/shelf/shelf_model.h"
 #include "ash/shelf/shelf_util.h"
 #include "ash/shelf/shelf_widget.h"
 #include "ash/shell.h"
 #include "ash/shell/window_watcher_shelf_item_delegate.h"
 #include "ash/shell_window_ids.h"
 #include "ui/aura/window.h"
 #include "ui/aura/window_event_dispatcher.h"
 #include "ui/gfx/display.h"
 
 namespace ash {
 namespace shell {
 
 class WindowWatcher::WorkspaceWindowWatcher : public aura::WindowObserver {
  public:
   explicit WorkspaceWindowWatcher(WindowWatcher* watcher) : watcher_(watcher) {
   }
 
-  virtual ~WorkspaceWindowWatcher() {
-  }
+  ~WorkspaceWindowWatcher() override {}
 
-  virtual void OnWindowAdded(aura::Window* new_window) override {
+  void OnWindowAdded(aura::Window* new_window) override {
     new_window->AddObserver(watcher_);
   }
 
-  virtual void OnWillRemoveWindow(aura::Window* window) override {
+  void OnWillRemoveWindow(aura::Window* window) override {
     DCHECK(window->children().empty());
     window->RemoveObserver(watcher_);
   }
 
   void RootWindowAdded(aura::Window* root) {
     aura::Window* panel_container =
         ash::Shell::GetContainer(root, kShellWindowId_PanelContainer);
     panel_container->AddObserver(watcher_);
 
     aura::Window* container =
@@ skipping 100 matching lines @@
 void WindowWatcher::OnDisplayRemoved(const gfx::Display& old_display) {
   // All windows in the display has already been removed, so no need to
   // remove observers.
 }
 
 void WindowWatcher::OnDisplayMetricsChanged(const gfx::Display&, uint32_t) {
 }
 
 }  // namespace shell
 }  // namespace ash