Standardize usage of virtual/override/final specifiers.

ash/wm/window_state.h

Index: ash/wm/window_state.h
diff --git a/ash/wm/window_state.h b/ash/wm/window_state.h
index a76555795790f6a637459c7e2bf390307dac3a05..cc4627377688ca92ec0d33fd2cbdc3ab6011d533 100644
--- a/ash/wm/window_state.h
+++ b/ash/wm/window_state.h
@@ -79,7 +79,7 @@ class ASH_EXPORT WindowState : public aura::WindowObserver {
   };
 
   // Call GetWindowState() to instantiate this class.
-  virtual ~WindowState();
+  ~WindowState() override;
 
   aura::Window* window() { return window_; }
   const aura::Window* window() const { return window_; }
@@ -298,9 +298,9 @@ class ASH_EXPORT WindowState : public aura::WindowObserver {
   DragDetails* drag_details() { return drag_details_.get(); }
 
   // aura::WindowObserver overrides:
-  virtual void OnWindowPropertyChanged(aura::Window* window,
-                                       const void* key,
-                                       intptr_t old) override;
+  void OnWindowPropertyChanged(aura::Window* window,
+                               const void* key,
+                               intptr_t old) override;
 
  private:
   friend class DefaultState;