Replace NULL with nullptr in all C++ files.

webrtc/voice_engine/test/channel_transport/udp_transport_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 100 matching lines @@
 TEST_F(UDPTransportTest, CreateTransport) {
   int32_t id = 0;
   uint8_t threads = 1;
   UdpTransport* transport = UdpTransport::Create(id, threads);
   UdpTransport::Destroy(transport);
 }
 
 // This test verifies that the mock_socket is not called from the constructor.
 TEST_F(UDPTransportTest, ConstructorDoesNotCreateSocket) {
   int32_t id = 0;
-  UdpTransportImpl::SocketFactoryInterface* null_maker = NULL;
-  UdpSocketManager* null_manager = NULL;
+  UdpTransportImpl::SocketFactoryInterface* null_maker = nullptr;
+  UdpSocketManager* null_manager = nullptr;
   UdpTransport* transport = new UdpTransportImpl(id,
                                                  null_maker,
                                                  null_manager);
   delete transport;
 }
 
 TEST_F(UDPTransportTest, InitializeSourcePorts) {
   int32_t id = 0;
   UdpTransportImpl::SocketFactoryInterface* mock_maker
       = new MockSocketFactory(sockets_created());
   MockUdpSocketManager* mock_manager = new MockUdpSocketManager();
   UdpTransport* transport = new UdpTransportImpl(id,
                                                  mock_maker,
                                                  mock_manager);
   EXPECT_EQ(0, transport->InitializeSourcePorts(4711, 4712));
   EXPECT_EQ(2u, NumSocketsCreated());
 
   delete transport;
   mock_manager->Destroy();
 }
 
 }  // namespace test
 }  // namespace webrtc