Standardize usage of virtual/override/final specifiers.

chrome/browser/signin/signin_error_notifier_ash.cc

Index: chrome/browser/signin/signin_error_notifier_ash.cc
diff --git a/chrome/browser/signin/signin_error_notifier_ash.cc b/chrome/browser/signin/signin_error_notifier_ash.cc
index cd61bb0314322d1e021b9df226e4023fbcf22fa8..d1f9f5818f07271d8e43bbe27f49f13fc2482b69 100644
--- a/chrome/browser/signin/signin_error_notifier_ash.cc
+++ b/chrome/browser/signin/signin_error_notifier_ash.cc
@@ -50,16 +50,16 @@ class SigninNotificationDelegate : public NotificationDelegate {
                              Profile* profile);
 
   // NotificationDelegate:
-  virtual void Display() override;
-  virtual void Error() override;
-  virtual void Close(bool by_user) override;
-  virtual bool HasClickedListener() override;
-  virtual void Click() override;
-  virtual void ButtonClick(int button_index) override;
-  virtual std::string id() const override;
+  void Display() override;
+  void Error() override;
+  void Close(bool by_user) override;
+  bool HasClickedListener() override;
+  void Click() override;
+  void ButtonClick(int button_index) override;
+  std::string id() const override;
 
  protected:
-  virtual ~SigninNotificationDelegate();
+  ~SigninNotificationDelegate() override;
 
  private:
   void FixSignIn();