Stop using some scoped_ptr features that unique_ptr doesn't have

webrtc/base/asyncudpsocket.cc

 /*
  *  Copyright 2004 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 19 matching lines @@
                                        const SocketAddress& bind_address) {
   AsyncSocket* socket =
       factory->CreateAsyncSocket(bind_address.family(), SOCK_DGRAM);
   if (!socket)
     return NULL;
   return Create(socket, bind_address);
 }
 
 AsyncUDPSocket::AsyncUDPSocket(AsyncSocket* socket)
     : socket_(socket) {
-  ASSERT(socket_);
   size_ = BUF_SIZE;
   buf_ = new char[size_];
 
   // The socket should start out readable but not writable.
   socket_->SignalReadEvent.connect(this, &AsyncUDPSocket::OnReadEvent);
   socket_->SignalWriteEvent.connect(this, &AsyncUDPSocket::OnWriteEvent);
 }
 
 AsyncUDPSocket::~AsyncUDPSocket() {
   delete [] buf_;
@@ skipping 68 matching lines @@
   // If we did not, then we should resize our buffer to be large enough.
   SignalReadPacket(this, buf_, static_cast<size_t>(len), remote_addr,
                    CreatePacketTime(0));
 }
 
 void AsyncUDPSocket::OnWriteEvent(AsyncSocket* socket) {
   SignalReadyToSend(this);
 }
 
 }  // namespace rtc