Standardize usage of virtual/override/final specifiers.

ash/sticky_keys/sticky_keys_overlay.h

Index: ash/sticky_keys/sticky_keys_overlay.h
diff --git a/ash/sticky_keys/sticky_keys_overlay.h b/ash/sticky_keys/sticky_keys_overlay.h
index 34ea266c58404c556e352226c916f4b33dbb1826..63917941a4c4bfe872d9b88ca35efa0bc5f69513 100644
--- a/ash/sticky_keys/sticky_keys_overlay.h
+++ b/ash/sticky_keys/sticky_keys_overlay.h
@@ -31,7 +31,7 @@ class StickyKeysOverlayView;
 class ASH_EXPORT StickyKeysOverlay : public ui::LayerAnimationObserver {
  public:
   StickyKeysOverlay();
-  virtual ~StickyKeysOverlay();
+  ~StickyKeysOverlay() override;
 
   // Shows or hides the overlay.
   void Show(bool visible);
@@ -56,12 +56,9 @@ class ASH_EXPORT StickyKeysOverlay : public ui::LayerAnimationObserver {
   gfx::Rect CalculateOverlayBounds();
 
   // gfx::LayerAnimationObserver overrides:
-  virtual void OnLayerAnimationEnded(
-      ui::LayerAnimationSequence* sequence) override;
-  virtual void OnLayerAnimationAborted(
-      ui::LayerAnimationSequence* sequence) override;
-  virtual void OnLayerAnimationScheduled(
-      ui::LayerAnimationSequence* sequence) override;
+  void OnLayerAnimationEnded(ui::LayerAnimationSequence* sequence) override;
+  void OnLayerAnimationAborted(ui::LayerAnimationSequence* sequence) override;
+  void OnLayerAnimationScheduled(ui::LayerAnimationSequence* sequence) override;
 
   bool is_visible_;
   scoped_ptr<views::Widget> overlay_widget_;