Replace NULL with nullptr in all C++ files.

webrtc/p2p/quic/quictransport.cc

 /*
  *  Copyright 2016 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 70 matching lines @@
   P2PTransportChannel* ice_channel =
       new P2PTransportChannel(name(), component, port_allocator());
   return new QuicTransportChannel(ice_channel);
 }
 
 void QuicTransport::DestroyTransportChannel(TransportChannelImpl* channel) {
   delete channel;
 }
 
 bool QuicTransport::GetSslRole(rtc::SSLRole* ssl_role) const {
-  RTC_DCHECK(ssl_role != NULL);
+  RTC_DCHECK(ssl_role != nullptr);
   *ssl_role = local_role_;
   return true;
 }
 
 bool QuicTransport::ApplyNegotiatedTransportDescription(
     TransportChannelImpl* channel,
     std::string* error_desc) {
   // Set ssl role and remote fingerprint. These are required for QUIC setup.
   if (!channel->SetSslRole(local_role_)) {
     return BadTransportDescription("Failed to set ssl role for the channel.",
                                    error_desc);
   }
   // Apply remote fingerprint.
   if (!channel->SetRemoteFingerprint(
           remote_fingerprint_->algorithm,
           reinterpret_cast<const uint8_t*>(remote_fingerprint_->digest.data()),
           remote_fingerprint_->digest.size())) {
     return BadTransportDescription("Failed to apply remote fingerprint.",
                                    error_desc);
   }
   return Transport::ApplyNegotiatedTransportDescription(channel, error_desc);
 }
 
 }  // namespace cricket