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

cloud_print/service/win/chrome_launcher.h

 // Copyright (c) 2012 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #ifndef CLOUD_PRINT_SERVICE_CHROME_LAUNCHER_H_
 #define CLOUD_PRINT_SERVICE_CHROME_LAUNCHER_H_
 
 #include <string>
 #include <vector>
 
 #include "base/basictypes.h"
 #include "base/files/file_path.h"
 #include "base/memory/scoped_ptr.h"
 #include "base/threading/simple_thread.h"
 
 class ChromeLauncher : public base::DelegateSimpleThread::Delegate {
  public:
   explicit ChromeLauncher(const base::FilePath& user_data);
 
-  virtual ~ChromeLauncher();
+  ~ChromeLauncher() override;
 
   bool Start();
   void Stop();
 
-  virtual void Run() override;
+  // base::DelegateSimpleThread::Delegate:
+  void Run() override;
 
   static std::string CreateServiceStateFile(
       const std::string& proxy_id,
       const std::vector<std::string>& printers);
 
  private:
   base::FilePath user_data_;
   base::WaitableEvent stop_event_;
   scoped_ptr<base::DelegateSimpleThread> thread_;
 
   DISALLOW_COPY_AND_ASSIGN(ChromeLauncher);
 };
 
 #endif  // CLOUD_PRINT_SERVICE_CHROME_LAUNCHER_H_