Standardize usage of virtual/override/final specifiers.

ash/wm/partial_screenshot_view.cc

Index: ash/wm/partial_screenshot_view.cc
diff --git a/ash/wm/partial_screenshot_view.cc b/ash/wm/partial_screenshot_view.cc
index 789ea1e90e58d6f1c3990e8a44ccc0f3761397bd..233a286d28398ee8186f27768594860e63dc930e 100644
--- a/ash/wm/partial_screenshot_view.cc
+++ b/ash/wm/partial_screenshot_view.cc
@@ -39,7 +39,7 @@ class PartialScreenshotView::OverlayDelegate
   }
 
   // Overridden from OverlayEventFilter::Delegate:
-  virtual void Cancel() override {
+  void Cancel() override {
     // Make sure the mouse_warp_mode allows warping. It can be stopped by a
     // partial screenshot view.
     MouseCursorEventFilter* mouse_cursor_filter =
@@ -50,18 +50,18 @@ class PartialScreenshotView::OverlayDelegate
       widgets_[i]->Close();
   }
 
-  virtual bool IsCancelingKeyEvent(ui::KeyEvent* event) override {
+  bool IsCancelingKeyEvent(ui::KeyEvent* event) override {
     return event->key_code() == ui::VKEY_ESCAPE;
   }
 
-  virtual aura::Window* GetWindow() override {
+  aura::Window* GetWindow() override {
     // Just returns NULL because this class does not handle key events in
     // OverlayEventFilter, except for cancel keys.
     return NULL;
   }
 
   // Overridden from views::WidgetObserver:
-  virtual void OnWidgetDestroying(views::Widget* widget) override {
+  void OnWidgetDestroying(views::Widget* widget) override {
     widget->RemoveObserver(this);
     widgets_.erase(std::remove(widgets_.begin(), widgets_.end(), widget));
     if (widgets_.empty())
@@ -69,7 +69,7 @@ class PartialScreenshotView::OverlayDelegate
   }
 
  private:
-  virtual ~OverlayDelegate() {
+  ~OverlayDelegate() override {
     Shell::GetInstance()->overlay_filter()->Deactivate(this);
   }