Replace NULL with nullptr in all C++ files.

webrtc/config.cc

 /*
  *  Copyright (c) 2014 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.
  */
 #include "webrtc/config.h"
@@ skipping 123 matching lines @@
   ss << "{content_type: ";
   switch (content_type) {
     case ContentType::kRealtimeVideo:
       ss << "kRealtimeVideo";
       break;
     case ContentType::kScreen:
       ss << "kScreenshare";
       break;
   }
   ss << ", encoder_specific_settings: ";
-  ss << (encoder_specific_settings != NULL ? "(ptr)" : "NULL");
+  ss << (encoder_specific_settings != nullptr ? "(ptr)" : "null");
 
   ss << ", min_transmit_bitrate_bps: " << min_transmit_bitrate_bps;
   ss << '}';
   return ss.str();
 }
 
 VideoEncoderConfig::VideoEncoderConfig(const VideoEncoderConfig&) = default;
 
 void VideoEncoderConfig::EncoderSpecificSettings::FillEncoderSpecificSettings(
     VideoCodec* codec) const {
@@ skipping 44 matching lines @@
 VideoEncoderConfig::Vp9EncoderSpecificSettings::Vp9EncoderSpecificSettings(
     const VideoCodecVP9& specifics)
     : specifics_(specifics) {}
 
 void VideoEncoderConfig::Vp9EncoderSpecificSettings::FillVideoCodecVp9(
     VideoCodecVP9* vp9_settings) const {
   *vp9_settings = specifics_;
 }
 
 }  // namespace webrtc