Replace NULL with nullptr in all C++ files.

webrtc/modules/rtp_rtcp/source/ulpfec_generator_unittest.cc

 /*
  *  Copyright (c) 2012 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 20 matching lines @@
 constexpr uint32_t kMediaSsrc = 835424;
 }  // namespace
 
 void VerifyHeader(uint16_t seq_num,
                   uint32_t timestamp,
                   int red_payload_type,
                   int fec_payload_type,
                   RedPacket* packet,
                   bool marker_bit) {
   EXPECT_GT(packet->length(), kRtpHeaderSize);
-  EXPECT_TRUE(packet->data() != NULL);
+  EXPECT_TRUE(packet->data() != nullptr);
   uint8_t* data = packet->data();
   // Marker bit not set.
   EXPECT_EQ(marker_bit ? 0x80 : 0, data[1] & 0x80);
   EXPECT_EQ(red_payload_type, data[1] & 0x7F);
   EXPECT_EQ(seq_num, (data[2] << 8) + data[3]);
   uint32_t parsed_timestamp =
       (data[4] << 24) + (data[5] << 16) + (data[6] << 8) + data[7];
   EXPECT_EQ(timestamp, parsed_timestamp);
   EXPECT_EQ(static_cast<uint8_t>(fec_payload_type), data[kRtpHeaderSize]);
 }
@@ skipping 143 matching lines @@
       packet->data, packet->length - kRtpHeaderSize, kRtpHeaderSize,
       kRedPayloadType);
   EXPECT_EQ(packet->length + kRedForFecHeaderLength, red_packet->length());
   VerifyHeader(packet->header.header.sequenceNumber,
                packet->header.header.timestamp, kRedPayloadType,
                packet->header.header.payloadType, red_packet.get(),
                true);  // Marker bit set.
 }
 
 }  // namespace webrtc