replace NULL->nullptr in src/remoting.

remoting/protocol/audio_reader.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/protocol/audio_reader.h"
 
 #include "base/bind.h"
 #include "net/socket/stream_socket.h"
 #include "remoting/base/constants.h"
 #include "remoting/protocol/session.h"
 #include "remoting/protocol/session_config.h"
 
 namespace remoting {
 namespace protocol {
 
 AudioReader::AudioReader(AudioPacket::Encoding encoding)
     : ChannelDispatcherBase(kAudioChannelName),
       encoding_(encoding),
-      audio_stub_(NULL) {
+      audio_stub_(nullptr) {
 }
 
 AudioReader::~AudioReader() {
 }
 
 // static
 scoped_ptr<AudioReader> AudioReader::Create(const SessionConfig& config) {
   if (!config.is_audio_enabled())
     return nullptr;
   return make_scoped_ptr(new AudioReader(AudioPacket::ENCODING_RAW));
 }
 
 void AudioReader::OnInitialized() {
   reader_.Init(channel(), base::Bind(&AudioReader::OnNewData,
                                      base::Unretained(this)));
 }
 
 void AudioReader::OnNewData(scoped_ptr<AudioPacket> packet,
                             const base::Closure& done_task) {
   audio_stub_->ProcessAudioPacket(packet.Pass(), done_task);
 }
 
 }  // namespace protocol
 }  // namespace remoting