replace NULL->nullptr in src/remoting.

remoting/host/pam_authorization_factory_posix.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.
 
 #include "remoting/host/pam_authorization_factory_posix.h"
 
 #include <security/pam_appl.h>
 
 #include "base/bind.h"
 #include "base/callback.h"
@@ skipping 93 matching lines @@
   if (local_login_status_ == NOT_CHECKED && state() == ACCEPTED) {
     local_login_status_ = IsLocalLoginAllowed() ? ALLOWED : DISALLOWED;
   }
 }
 
 bool PamAuthorizer::IsLocalLoginAllowed() {
   std::string username = GetUsername();
   if (username.empty()) {
     return false;
   }
-  struct pam_conv conv = { PamConversation, NULL };
-  pam_handle_t* handle = NULL;
+  struct pam_conv conv = { PamConversation, nullptr };
+  pam_handle_t* handle = nullptr;
   int result = pam_start("chrome-remote-desktop", username.c_str(),
                          &conv, &handle);
   if (result == PAM_SUCCESS) {
     result = pam_acct_mgmt(handle, 0);
   }
   pam_end(handle, result);
 
   HOST_LOG << "Local login check for " << username
             << (result == PAM_SUCCESS ? " succeeded." : " failed.");
 
@@ skipping 43 matching lines @@
     const std::string& local_jid,
     const std::string& remote_jid,
     const buzz::XmlElement* first_message) {
   scoped_ptr<protocol::Authenticator> authenticator(
       underlying_->CreateAuthenticator(local_jid, remote_jid, first_message));
   return make_scoped_ptr(new PamAuthorizer(authenticator.Pass()));
 }
 
 
 }  // namespace remoting