Update {virtual,override} to follow C++11 style in remoting.

remoting/host/desktop_session_win.h

Index: remoting/host/desktop_session_win.h
diff --git a/remoting/host/desktop_session_win.h b/remoting/host/desktop_session_win.h
index 3e21a02917dd46e7f33e1ed70a95da89fea60d62..933be24f0a65a1702b14d169b7cb010d4f2773ed 100644
--- a/remoting/host/desktop_session_win.h
+++ b/remoting/host/desktop_session_win.h
@@ -63,7 +63,7 @@ class DesktopSessionWin
     DaemonProcess* daemon_process,
     int id,
     WtsTerminalMonitor* monitor);
-  virtual ~DesktopSessionWin();
+  ~DesktopSessionWin() override;
 
   const scoped_refptr<AutoThreadTaskRunner>& caller_task_runner() const {
     return caller_task_runner_;
@@ -85,13 +85,13 @@ class DesktopSessionWin
   virtual void InjectSas() = 0;
 
   // WorkerProcessIpcDelegate implementation.
-  virtual void OnChannelConnected(int32 peer_pid) override;
-  virtual bool OnMessageReceived(const IPC::Message& message) override;
-  virtual void OnPermanentError(int exit_code) override;
+  void OnChannelConnected(int32 peer_pid) override;
+  bool OnMessageReceived(const IPC::Message& message) override;
+  void OnPermanentError(int exit_code) override;
 
   // WtsTerminalObserver implementation.
-  virtual void OnSessionAttached(uint32 session_id) override;
-  virtual void OnSessionDetached() override;
+  void OnSessionAttached(uint32 session_id) override;
+  void OnSessionDetached() override;
 
  private:
   // ChromotingDesktopDaemonMsg_DesktopAttached handler.