Standardize usage of virtual/override/final specifiers.

ash/shelf/shelf_tooltip_manager.h

Index: ash/shelf/shelf_tooltip_manager.h
diff --git a/ash/shelf/shelf_tooltip_manager.h b/ash/shelf/shelf_tooltip_manager.h
index 96c72592994c159f8363053262cc0e1d0f64f523..512c6e58654d506a13649da5add514bb29038d5a 100644
--- a/ash/shelf/shelf_tooltip_manager.h
+++ b/ash/shelf/shelf_tooltip_manager.h
@@ -40,7 +40,7 @@ class ASH_EXPORT ShelfTooltipManager : public ui::EventHandler,
  public:
   ShelfTooltipManager(ShelfLayoutManager* shelf_layout_manager,
                       ShelfView* shelf_view);
-  virtual ~ShelfTooltipManager();
+  ~ShelfTooltipManager() override;
 
   ShelfLayoutManager* shelf_layout_manager() { return shelf_layout_manager_; }
 
@@ -78,16 +78,15 @@ class ASH_EXPORT ShelfTooltipManager : public ui::EventHandler,
 
 protected:
   // ui::EventHandler overrides:
-  virtual void OnMouseEvent(ui::MouseEvent* event) override;
-  virtual void OnTouchEvent(ui::TouchEvent* event) override;
-  virtual void OnGestureEvent(ui::GestureEvent* event) override;
-  virtual void OnCancelMode(ui::CancelModeEvent* event) override;
+ void OnMouseEvent(ui::MouseEvent* event) override;
+ void OnTouchEvent(ui::TouchEvent* event) override;
+ void OnGestureEvent(ui::GestureEvent* event) override;
+ void OnCancelMode(ui::CancelModeEvent* event) override;
 
   // ShelfLayoutManagerObserver overrides:
-  virtual void WillDeleteShelf() override;
-  virtual void WillChangeVisibilityState(
-      ShelfVisibilityState new_state) override;
-  virtual void OnAutoHideStateChanged(ShelfAutoHideState new_state) override;
+ void WillDeleteShelf() override;
+ void WillChangeVisibilityState(ShelfVisibilityState new_state) override;
+ void OnAutoHideStateChanged(ShelfAutoHideState new_state) override;
 
  private:
   class ShelfTooltipBubble;