Replace NULL with nullptr in all C++ files.

webrtc/pc/channel.cc

Index: webrtc/pc/channel.cc
diff --git a/webrtc/pc/channel.cc b/webrtc/pc/channel.cc
index 02d93f79e760968226aac953a4fa01565fbeb7b3..3e4a34b80657fb7552225b9c5e4408a8ce96399c 100644
--- a/webrtc/pc/channel.cc
+++ b/webrtc/pc/channel.cc
@@ -125,8 +125,8 @@ static bool IsSendContentDirection(MediaContentDirection direction) {
 
 static const MediaContentDescription* GetContentDescription(
     const ContentInfo* cinfo) {
-  if (cinfo == NULL)
-    return NULL;
+  if (cinfo == nullptr)
+    return nullptr;
   return static_cast<const MediaContentDescription*>(cinfo->description);
 }
 
@@ -184,7 +184,7 @@ BaseChannel::~BaseChannel() {
   worker_thread_->Clear(&invoker_);
   worker_thread_->Clear(this);
   // We must destroy the media channel before the transport channel, otherwise
-  // the media channel may try to send on the dead transport channel. NULLing
+  // the media channel may try to send on the dead transport channel. nulling
   // is not an effective strategy since the sends will come on another thread.
   delete media_channel_;
   LOG(LS_INFO) << "Destroyed channel: " << content_name_;
@@ -254,7 +254,7 @@ bool BaseChannel::InitNetwork_n(
 
 void BaseChannel::Deinit() {
   RTC_DCHECK(worker_thread_->IsCurrent());
-  media_channel_->SetInterface(NULL);
+  media_channel_->SetInterface(nullptr);
   // Packets arrive on the network thread, processing packets calls virtual
   // functions, so need to stop this process in Deinit that is called in
   // derived classes destructor.
@@ -747,7 +747,7 @@ bool BaseChannel::SendPacket(bool rtcp,
           &updated_options.packet_time_params.srtp_packet_index);
       // If protection succeeds, let's get auth params from srtp.
       if (res) {
-        uint8_t* auth_key = NULL;
+        uint8_t* auth_key = nullptr;
         int key_len;
         res = srtp_filter_.GetRtpAuthParams(
             &auth_key, &key_len,
@@ -1051,8 +1051,9 @@ bool BaseChannel::SetupDtlsSrtp_n(bool rtcp) {
   std::vector<unsigned char> dtls_buffer(key_len * 2 + salt_len * 2);
 
   // RFC 5705 exporter using the RFC 5764 parameters
-  if (!transport->ExportKeyingMaterial(kDtlsSrtpExporterLabel, NULL, 0, false,
-                                       &dtls_buffer[0], dtls_buffer.size())) {
+  if (!transport->ExportKeyingMaterial(kDtlsSrtpExporterLabel, nullptr, 0,
+                                       false, &dtls_buffer[0],
+                                       dtls_buffer.size())) {
     LOG(LS_WARNING) << "DTLS-SRTP key export failed";
     RTC_NOTREACHED();  // This should never happen
     return false;
@@ -1682,7 +1683,7 @@ void VoiceChannel::StopAudioMonitor() {
 }
 
 bool VoiceChannel::IsAudioMonitorRunning() const {
-  return (audio_monitor_.get() != NULL);
+  return (audio_monitor_.get() != nullptr);
 }
 
 int VoiceChannel::GetInputLevel_w() {
@@ -1786,7 +1787,7 @@ bool VoiceChannel::SetLocalContent_w(const MediaContentDescription* content,
 
   const AudioContentDescription* audio =
       static_cast<const AudioContentDescription*>(content);
-  RTC_DCHECK(audio != NULL);
+  RTC_DCHECK(audio != nullptr);
   if (!audio) {
     SafeSetError("Can't find audio content in local description.", error_desc);
     return false;
@@ -1831,7 +1832,7 @@ bool VoiceChannel::SetRemoteContent_w(const MediaContentDescription* content,
 
   const AudioContentDescription* audio =
       static_cast<const AudioContentDescription*>(content);
-  RTC_DCHECK(audio != NULL);
+  RTC_DCHECK(audio != nullptr);
   if (!audio) {
     SafeSetError("Can't find audio content in remote description.", error_desc);
     return false;
@@ -2064,7 +2065,7 @@ bool VideoChannel::SetLocalContent_w(const MediaContentDescription* content,
 
   const VideoContentDescription* video =
       static_cast<const VideoContentDescription*>(content);
-  RTC_DCHECK(video != NULL);
+  RTC_DCHECK(video != nullptr);
   if (!video) {
     SafeSetError("Can't find video content in local description.", error_desc);
     return false;
@@ -2109,7 +2110,7 @@ bool VideoChannel::SetRemoteContent_w(const MediaContentDescription* content,
 
   const VideoContentDescription* video =
       static_cast<const VideoContentDescription*>(content);
-  RTC_DCHECK(video != NULL);
+  RTC_DCHECK(video != nullptr);
   if (!video) {
     SafeSetError("Can't find video content in remote description.", error_desc);
     return false;
@@ -2260,7 +2261,7 @@ bool RtpDataChannel::SetLocalContent_w(const MediaContentDescription* content,
 
   const DataContentDescription* data =
       static_cast<const DataContentDescription*>(content);
-  RTC_DCHECK(data != NULL);
+  RTC_DCHECK(data != nullptr);
   if (!data) {
     SafeSetError("Can't find data content in local description.", error_desc);
     return false;
@@ -2308,7 +2309,7 @@ bool RtpDataChannel::SetRemoteContent_w(const MediaContentDescription* content,
 
   const DataContentDescription* data =
       static_cast<const DataContentDescription*>(content);
-  RTC_DCHECK(data != NULL);
+  RTC_DCHECK(data != nullptr);
   if (!data) {
     SafeSetError("Can't find data content in remote description.", error_desc);
     return false;