Standardize usage of virtual/override/final specifiers.

ash/shell/widgets.cc

Index: ash/shell/widgets.cc
diff --git a/ash/shell/widgets.cc b/ash/shell/widgets.cc
index 43044149c884917078845420ae7fceddecf1a657..3db77271d4927b7629fd5a5eab8daf366ab775bb 100644
--- a/ash/shell/widgets.cc
+++ b/ash/shell/widgets.cc
@@ -27,17 +27,17 @@ const int kWindowHeight = 400;
 class WidgetsWindow : public views::WidgetDelegateView {
  public:
   WidgetsWindow();
-  virtual ~WidgetsWindow();
+  ~WidgetsWindow() override;
 
   // Overridden from views::View:
-  virtual void OnPaint(gfx::Canvas* canvas) override;
-  virtual void Layout() override;
-  virtual gfx::Size GetPreferredSize() const override;
+  void OnPaint(gfx::Canvas* canvas) override;
+  void Layout() override;
+  gfx::Size GetPreferredSize() const override;
 
   // Overridden from views::WidgetDelegate:
-  virtual views::View* GetContentsView() override;
-  virtual base::string16 GetWindowTitle() const override;
-  virtual bool CanResize() const override;
+  views::View* GetContentsView() override;
+  base::string16 GetWindowTitle() const override;
+  bool CanResize() const override;
 
  private:
   views::LabelButton* button_;