Standardize usage of virtual/override/final specifiers.

ash/wm/overview/window_selector_window.h

Index: ash/wm/overview/window_selector_window.h
diff --git a/ash/wm/overview/window_selector_window.h b/ash/wm/overview/window_selector_window.h
index 4fca437640a46f8c62930d282270aa4d33e5c5da..915e0f84f7fe9fe530e33d2dbe00d8d8539614ba 100644
--- a/ash/wm/overview/window_selector_window.h
+++ b/ash/wm/overview/window_selector_window.h
@@ -25,21 +25,21 @@ namespace ash {
 class WindowSelectorWindow : public WindowSelectorItem {
  public:
   explicit WindowSelectorWindow(aura::Window* window);
-  virtual ~WindowSelectorWindow();
+  ~WindowSelectorWindow() override;
 
   // WindowSelectorItem:
-  virtual aura::Window* GetRootWindow() override;
-  virtual bool HasSelectableWindow(const aura::Window* window) override;
-  virtual bool Contains(const aura::Window* target) override;
-  virtual void RestoreWindowOnExit(aura::Window* window) override;
-  virtual aura::Window* SelectionWindow() override;
-  virtual void RemoveWindow(const aura::Window* window) override;
-  virtual bool empty() const override;
-  virtual void PrepareForOverview() override;
-  virtual void SetItemBounds(aura::Window* root_window,
-                             const gfx::Rect& target_bounds,
-                             bool animate) override;
-  virtual void SetOpacity(float opacity) override;
+  aura::Window* GetRootWindow() override;
+  bool HasSelectableWindow(const aura::Window* window) override;
+  bool Contains(const aura::Window* target) override;
+  void RestoreWindowOnExit(aura::Window* window) override;
+  aura::Window* SelectionWindow() override;
+  void RemoveWindow(const aura::Window* window) override;
+  bool empty() const override;
+  void PrepareForOverview() override;
+  void SetItemBounds(aura::Window* root_window,
+                     const gfx::Rect& target_bounds,
+                     bool animate) override;
+  void SetOpacity(float opacity) override;
 
  private:
   // The window with a scoped transform represented by this selector item.