Standardize usage of virtual/override/final specifiers.

components/constrained_window/constrained_window_views.cc

Index: components/constrained_window/constrained_window_views.cc
diff --git a/components/constrained_window/constrained_window_views.cc b/components/constrained_window/constrained_window_views.cc
index 43d48307336927b8f9a16aebd5006856c265a4e6..68664fbe93579fbd3700a0f7270996df382602ef 100644
--- a/components/constrained_window/constrained_window_views.cc
+++ b/components/constrained_window/constrained_window_views.cc
@@ -43,7 +43,7 @@ class WidgetModalDialogHostObserverViews
     target_widget_->AddObserver(this);
   }
 
-  virtual ~WidgetModalDialogHostObserverViews() {
+  ~WidgetModalDialogHostObserverViews() override {
     if (host_)
       host_->RemoveObserver(this);
     target_widget_->RemoveObserver(this);
@@ -51,16 +51,14 @@ class WidgetModalDialogHostObserverViews
   }
 
   // WidgetObserver overrides
-  virtual void OnWidgetClosing(views::Widget* widget) override {
-    delete this;
-  }
+  void OnWidgetClosing(views::Widget* widget) override { delete this; }
 
   // WebContentsModalDialogHostObserver overrides
-  virtual void OnPositionRequiresUpdate() override {
+  void OnPositionRequiresUpdate() override {
     UpdateWidgetModalDialogPosition(target_widget_, host_);
   }
 
-  virtual void OnHostDestroying() override {
+  void OnHostDestroying() override {
     host_->RemoveObserver(this);
     host_ = NULL;
   }