replace NULL->nullptr in src/remoting.

remoting/host/setup/start_host.cc

 // 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.
 //
 // A simple command-line app that registers and starts a host.
 
 #include <stdio.h>
 
 #include "base/at_exit.h"
 #include "base/command_line.h"
@@ skipping 11 matching lines @@
 #if !defined(OS_WIN)
 #include <termios.h>
 #endif  // !defined(OS_WIN)
 
 using remoting::HostStarter;
 
 // True if the host was started successfully.
 bool g_started = false;
 
 // The main message loop.
-base::MessageLoop* g_message_loop = NULL;
+base::MessageLoop* g_message_loop = nullptr;
 
 // Lets us hide the PIN that a user types.
 void SetEcho(bool echo) {
 #if defined(OS_WIN)
   DWORD mode;
   HANDLE console_handle = GetStdHandle(STD_INPUT_HANDLE);
   if (!GetConsoleMode(console_handle, &mode)) {
     LOG(ERROR) << "GetConsoleMode failed";
     return;
   }
@@ skipping 135 matching lines @@
   if (redirect_url.empty()) {
     redirect_url = remoting::GetDefaultOauthRedirectUrl();
   }
   host_starter->StartHost(host_name, host_pin, true, auth_code, redirect_url,
                           base::Bind(&OnDone));
 
   // Run the message loop until the StartHost completion callback.
   base::RunLoop run_loop;
   run_loop.Run();
 
-  g_message_loop = NULL;
+  g_message_loop = nullptr;
 
   // Destroy the HostStarter and URLRequestContextGetter before stopping the
   // IO thread.
   host_starter.reset();
-  url_request_context_getter = NULL;
+  url_request_context_getter = nullptr;
 
   io_thread.Stop();
 
   return g_started ? 0 : 1;
 }