Standardize usage of virtual/override/final in remoting/

remoting/host/host_change_notification_listener.h

Index: remoting/host/host_change_notification_listener.h
diff --git a/remoting/host/host_change_notification_listener.h b/remoting/host/host_change_notification_listener.h
index e7ff2fef521d58c1fa8db0999a69ca8d2e9d2c5e..c24f74b138cb09fec50dd6b0882bcc3a625d539e 100644
--- a/remoting/host/host_change_notification_listener.h
+++ b/remoting/host/host_change_notification_listener.h
@@ -37,13 +37,11 @@ class HostChangeNotificationListener : public SignalStrategy::Listener {
                                  const std::string& host_id,
                                  SignalStrategy* signal_strategy,
                                  const std::string& directory_bot_jid);
-  virtual ~HostChangeNotificationListener();
+  ~HostChangeNotificationListener() override;
 
   // SignalStrategy::Listener interface.
-  virtual void OnSignalStrategyStateChange(
-      SignalStrategy::State state) override;
-  virtual bool OnSignalStrategyIncomingStanza(
-      const buzz::XmlElement* stanza) override;
+  void OnSignalStrategyStateChange(SignalStrategy::State state) override;
+  bool OnSignalStrategyIncomingStanza(const buzz::XmlElement* stanza) override;
 
  private:
   void OnHostDeleted();