Use the location where FileDescriptorWatcher is created to track the libevent handlers

net/socket/udp_socket_posix.cc

 // Copyright (c) 2012 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "net/socket/udp_socket_posix.h"
 
 #include <errno.h>
 #include <fcntl.h>
 #include <net/if.h>
 #include <netdb.h>
@@ skipping 144 matching lines @@
                                net::NetLog* net_log,
                                const net::NetLogSource& source)
     : socket_(kInvalidSocket),
       addr_family_(0),
       is_connected_(false),
       socket_options_(SOCKET_OPTION_MULTICAST_LOOP),
       multicast_interface_(0),
       multicast_time_to_live_(1),
       bind_type_(bind_type),
       rand_int_cb_(rand_int_cb),
+      read_socket_watcher_(FROM_HERE),
+      write_socket_watcher_(FROM_HERE),
       read_watcher_(this),
       write_watcher_(this),
       read_buf_len_(0),
       recv_from_address_(NULL),
       write_buf_len_(0),
       net_log_(NetLogWithSource::Make(net_log, NetLogSourceType::UDP_SOCKET)),
       bound_network_(NetworkChangeNotifier::kInvalidNetworkHandle) {
   net_log_.BeginEvent(NetLogEventType::SOCKET_ALIVE,
                       source.ToEventParametersCallback());
   if (bind_type == DatagramSocket::RANDOM_BIND)
@@ skipping 788 matching lines @@
     return MapSystemError(errno);
 
   return OK;
 }
 
 void UDPSocketPosix::DetachFromThread() {
   base::NonThreadSafe::DetachFromThread();
 }
 
 }  // namespace net