Standardize usage of virtual/override/final specifiers.

ash/desktop_background/desktop_background_widget_controller.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/desktop_background/desktop_background_widget_controller.h"
 
 #include "ash/ash_export.h"
 #include "ash/desktop_background/user_wallpaper_delegate.h"
 #include "ash/root_window_controller.h"
 #include "ash/shell.h"
@@ skipping 12 matching lines @@
   ShowWallpaperAnimationObserver(RootWindowController* root_window_controller,
                                  views::Widget* desktop_widget,
                                  bool is_initial_animation)
       : root_window_controller_(root_window_controller),
         desktop_widget_(desktop_widget),
         is_initial_animation_(is_initial_animation) {
     DCHECK(desktop_widget_);
     desktop_widget_->AddObserver(this);
   }
 
-  virtual ~ShowWallpaperAnimationObserver() {
+  ~ShowWallpaperAnimationObserver() override {
     StopObservingImplicitAnimations();
     if (desktop_widget_)
       desktop_widget_->RemoveObserver(this);
   }
 
  private:
   // Overridden from ui::ImplicitAnimationObserver:
-  virtual void OnImplicitAnimationsScheduled() override {
+  void OnImplicitAnimationsScheduled() override {
     if (is_initial_animation_) {
       root_window_controller_->
           HandleInitialDesktopBackgroundAnimationStarted();
     }
   }
 
-  virtual void OnImplicitAnimationsCompleted() override {
+  void OnImplicitAnimationsCompleted() override {
     root_window_controller_->OnWallpaperAnimationFinished(desktop_widget_);
     delete this;
   }
 
   // Overridden from views::WidgetObserver.
-  virtual void OnWidgetDestroying(views::Widget* widget) override {
-    delete this;
-  }
+  void OnWidgetDestroying(views::Widget* widget) override { delete this; }
 
   RootWindowController* root_window_controller_;
   views::Widget* desktop_widget_;
 
   // Is this object observing the initial brightness/grayscale animation?
   const bool is_initial_animation_;
 
   DISALLOW_COPY_AND_ASSIGN(ShowWallpaperAnimationObserver);
 };
 
@@ skipping 70 matching lines @@
 }
 
 DesktopBackgroundWidgetController* AnimatingDesktopController::GetController(
     bool pass_ownership) {
   if (pass_ownership)
     return controller_.release();
   return controller_.get();
 }
 
 }  // namespace ash