Replace NULL with nullptr in all C++ files.

webrtc/pc/channelmanager.cc

 /*
  *  Copyright 2004 The WebRTC project authors. All Rights Reserved.
  *
  *  Use of this source code is governed by a BSD-style license
  *  that can be found in the LICENSE file in the root of the source
  *  tree. An additional intellectual property rights grant can be found
  *  in the file PATENTS.  All contributing project authors may
  *  be found in the AUTHORS file in the root of the source tree.
  */
 
@@ skipping 172 matching lines @@
   if (!initialized_) {
     return;
   }
   worker_thread_->Invoke<void>(RTC_FROM_HERE,
                                Bind(&ChannelManager::Terminate_w, this));
   initialized_ = false;
 }
 
 void ChannelManager::DestructorDeletes_w() {
   RTC_DCHECK(worker_thread_ == rtc::Thread::Current());
-  media_engine_.reset(NULL);
+  media_engine_.reset(nullptr);
 }
 
 void ChannelManager::Terminate_w() {
   RTC_DCHECK(worker_thread_ == rtc::Thread::Current());
   // Need to destroy the voice/video channels
   while (!video_channels_.empty()) {
     DestroyVideoChannel_w(video_channels_.back());
   }
   while (!voice_channels_.empty()) {
     DestroyVoiceChannel_w(voice_channels_.back());
@@ skipping 98 matching lines @@
     const std::string& content_name,
     const std::string* bundle_transport_name,
     bool rtcp_mux_required,
     bool srtp_required,
     const VideoOptions& options) {
   RTC_DCHECK(initialized_);
   RTC_DCHECK(worker_thread_ == rtc::Thread::Current());
   RTC_DCHECK(nullptr != media_controller);
   VideoMediaChannel* media_channel = media_engine_->CreateVideoChannel(
       media_controller->call_w(), media_controller->config(), options);
-  if (media_channel == NULL) {
-    return NULL;
+  if (media_channel == nullptr) {
+    return nullptr;
   }
 
   VideoChannel* video_channel = new VideoChannel(
       worker_thread_, network_thread_, signaling_thread, media_channel,
       content_name, rtcp_mux_required, srtp_required);
   video_channel->SetCryptoOptions(crypto_options_);
   if (!video_channel->Init_w(rtp_transport, rtcp_transport, rtp_transport,
                              rtcp_transport)) {
     delete video_channel;
-    return NULL;
+    return nullptr;
   }
   video_channels_.push_back(video_channel);
   return video_channel;
 }
 
 void ChannelManager::DestroyVideoChannel(VideoChannel* video_channel) {
   TRACE_EVENT0("webrtc", "ChannelManager::DestroyVideoChannel");
   if (video_channel) {
     worker_thread_->Invoke<void>(
         RTC_FROM_HERE,
@@ skipping 97 matching lines @@
                           media_engine_.get(), file, max_size_bytes));
 }
 
 void ChannelManager::StopAecDump() {
   worker_thread_->Invoke<void>(
       RTC_FROM_HERE,
       Bind(&MediaEngineInterface::StopAecDump, media_engine_.get()));
 }
 
 }  // namespace cricket