Standardize usage of virtual/override/final specifiers.

ash/test/test_user_wallpaper_delegate.h

Index: ash/test/test_user_wallpaper_delegate.h
diff --git a/ash/test/test_user_wallpaper_delegate.h b/ash/test/test_user_wallpaper_delegate.h
index dc813bc3b03709a761d1b5e35cbfec95694735d9..d2d49fc08d8482b586042bb51206ce1e4a19ae2c 100644
--- a/ash/test/test_user_wallpaper_delegate.h
+++ b/ash/test/test_user_wallpaper_delegate.h
@@ -15,14 +15,14 @@ namespace test {
 class TestUserWallpaperDelegate : public DefaultUserWallpaperDelegate {
  public:
   TestUserWallpaperDelegate();
-  virtual ~TestUserWallpaperDelegate();
+  ~TestUserWallpaperDelegate() override;
 
   void set_custom_wallpaper(const gfx::ImageSkia& wallpaper) {
     custom_wallpaper_ = wallpaper;
   }
 
   // DefaultUserWallpaperDelegate overrides:
-  virtual void UpdateWallpaper(bool clear_cache) override;
+  void UpdateWallpaper(bool clear_cache) override;
 
   // Returns and clears |update_wallpaper_count_|.
   int GetUpdateWallpaperCountAndReset();