Standardize usage of virtual/override/final in remoting/

remoting/host/host_status_sender.h

Index: remoting/host/host_status_sender.h
diff --git a/remoting/host/host_status_sender.h b/remoting/host/host_status_sender.h
index b3ce5e45994578dfe597b697c8732af038a120c9..d1e14aecb58a8e2a33916fec12188c15200ecb00 100644
--- a/remoting/host/host_status_sender.h
+++ b/remoting/host/host_status_sender.h
@@ -59,13 +59,11 @@ class HostStatusSender : SignalStrategy::Listener {
                    SignalStrategy* signal_strategy,
                    scoped_refptr<RsaKeyPair> key_pair,
                    const std::string& directory_bot_jid);
-  virtual ~HostStatusSender();
+  ~HostStatusSender() 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;
 
   // APIs for sending host status XMPP messages to the chromoting bot.
   // status: the reason (exit code) why the host is offline.