Replace NULL with nullptr in all C++ files.

webrtc/pc/webrtcsession.cc

Index: webrtc/pc/webrtcsession.cc
diff --git a/webrtc/pc/webrtcsession.cc b/webrtc/pc/webrtcsession.cc
index e59466c67ba1bdd574d5011b20db0d3676fd8996..d933221d882a53c9e294cfcaedcc833c742a0f7e 100644
--- a/webrtc/pc/webrtcsession.cc
+++ b/webrtc/pc/webrtcsession.cc
@@ -234,7 +234,7 @@ static bool VerifyIceUfragPwdPresent(const SessionDescription* desc) {
 static bool GetTrackIdBySsrc(const SessionDescription* session_description,
                              uint32_t ssrc,
                              std::string* track_id) {
-  RTC_DCHECK(track_id != NULL);
+  RTC_DCHECK(track_id != nullptr);
 
   const cricket::ContentInfo* audio_info =
       cricket::GetFirstAudioContent(session_description);
@@ -455,13 +455,13 @@ WebRtcSession::WebRtcSession(
       sctp_factory_(std::move(sctp_factory)),
       media_controller_(media_controller),
       channel_manager_(media_controller_->channel_manager()),
-      ice_observer_(NULL),
+      ice_observer_(nullptr),
       ice_connection_state_(PeerConnectionInterface::kIceConnectionNew),
       ice_connection_receiving_(true),
       older_version_remote_peer_(false),
       dtls_enabled_(false),
       data_channel_type_(cricket::DCT_NONE),
-      metrics_observer_(NULL) {
+      metrics_observer_(nullptr) {
   transport_controller_->SetIceRole(cricket::ICEROLE_CONTROLLED);
   transport_controller_->SignalConnectionState.connect(
       this, &WebRtcSession::OnTransportControllerConnectionState);
@@ -1110,12 +1110,12 @@ bool WebRtcSession::ProcessIceMessage(const IceCandidateInterface* candidate) {
   }
 
   if (!candidate) {
-    LOG(LS_ERROR) << "ProcessIceMessage: Candidate is NULL.";
+    LOG(LS_ERROR) << "ProcessIceMessage: Candidate is null.";
     return false;
   }
 
   bool valid = false;
-  bool ready = ReadyToUseRemoteCandidate(candidate, NULL, &valid);
+  bool ready = ReadyToUseRemoteCandidate(candidate, nullptr, &valid);
   if (!valid) {
     return false;
   }
@@ -1230,7 +1230,7 @@ bool WebRtcSession::SendData(const cricket::SendDataParams& params,
                              cricket::SendDataResult* result) {
   if (!rtp_data_channel_ && !sctp_transport_) {
     LOG(LS_ERROR) << "SendData called when rtp_data_channel_ "
-                  << "and sctp_transport_ are NULL.";
+                  << "and sctp_transport_ are null.";
     return false;
   }
   return rtp_data_channel_
@@ -1267,7 +1267,7 @@ bool WebRtcSession::ConnectDataChannel(DataChannel* webrtc_data_channel) {
 void WebRtcSession::DisconnectDataChannel(DataChannel* webrtc_data_channel) {
   if (!rtp_data_channel_ && !sctp_transport_) {
     LOG(LS_ERROR) << "DisconnectDataChannel called when rtp_data_channel_ and "
-                     "sctp_transport_ are NULL.";
+                     "sctp_transport_ are null.";
     return;
   }
   if (rtp_data_channel_) {
@@ -1282,7 +1282,7 @@ void WebRtcSession::DisconnectDataChannel(DataChannel* webrtc_data_channel) {
 
 void WebRtcSession::AddSctpDataStream(int sid) {
   if (!sctp_transport_) {
-    LOG(LS_ERROR) << "AddSctpDataStream called when sctp_transport_ is NULL.";
+    LOG(LS_ERROR) << "AddSctpDataStream called when sctp_transport_ is null.";
     return;
   }
   network_thread_->Invoke<void>(
@@ -1293,7 +1293,7 @@ void WebRtcSession::AddSctpDataStream(int sid) {
 void WebRtcSession::RemoveSctpDataStream(int sid) {
   if (!sctp_transport_) {
     LOG(LS_ERROR) << "RemoveSctpDataStream called when sctp_transport_ is "
-                  << "NULL.";
+                  << "null.";
     return;
   }
   network_thread_->Invoke<void>(
@@ -1997,13 +1997,13 @@ bool WebRtcSession::ValidateBundleSettings(const SessionDescription* desc) {
 
   const cricket::ContentGroup* bundle_group =
       desc->GetGroupByName(cricket::GROUP_TYPE_BUNDLE);
-  RTC_DCHECK(bundle_group != NULL);
+  RTC_DCHECK(bundle_group != nullptr);
 
   const cricket::ContentInfos& contents = desc->contents();
   for (cricket::ContentInfos::const_iterator citer = contents.begin();
        citer != contents.end(); ++citer) {
     const cricket::ContentInfo* content = (&*citer);
-    RTC_DCHECK(content != NULL);
+    RTC_DCHECK(content != nullptr);
     if (bundle_group->HasContentName(content->name) &&
         !content->rejected && content->type == cricket::NS_JINGLE_RTP) {
       if (!HasRtcpMuxEnabled(content))
@@ -2198,7 +2198,7 @@ void WebRtcSession::ReportTransportStats() {
 // for IPv4 and IPv6.
 void WebRtcSession::ReportBestConnectionState(
     const cricket::TransportStats& stats) {
-  RTC_DCHECK(metrics_observer_ != NULL);
+  RTC_DCHECK(metrics_observer_ != nullptr);
   for (cricket::TransportChannelStatsList::const_iterator it =
          stats.channel_stats.begin();
        it != stats.channel_stats.end(); ++it) {
@@ -2248,7 +2248,7 @@ void WebRtcSession::ReportBestConnectionState(
 
 void WebRtcSession::ReportNegotiatedCiphers(
     const cricket::TransportStats& stats) {
-  RTC_DCHECK(metrics_observer_ != NULL);
+  RTC_DCHECK(metrics_observer_ != nullptr);
   if (!dtls_enabled_ || stats.channel_stats.empty()) {
     return;
   }