Change HostResolver::Resolve() to take an std::unique_ptr<Request>* rather than a RequestHandle*

extensions/browser/api/sockets_udp/sockets_udp_api.cc

 // Copyright 2014 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 "extensions/browser/api/sockets_udp/sockets_udp_api.h"
 
 #include "content/public/common/socket_permission_request.h"
 #include "extensions/browser/api/socket/udp_socket.h"
 #include "extensions/browser/api/sockets_udp/udp_socket_event_dispatcher.h"
 #include "extensions/common/api/sockets/sockets_manifest_data.h"
@@ skipping 233 matching lines @@
 
   StartDnsLookup(net::HostPortPair(params_->address, params_->port));
 }
 
 void SocketsUdpSendFunction::AfterDnsLookup(int lookup_result) {
   if (lookup_result == net::OK) {
     StartSendTo();
   } else {
     SetSendResult(lookup_result, -1);
   }
+
+  // TODO(maksims): investigate why std::unique_ptr<HostResolver::Request>'s
+  // destructor is not called automatically.
+  request_handle_.reset();
 }
 
 void SocketsUdpSendFunction::StartSendTo() {
   ResumableUDPSocket* socket = GetUdpSocket(params_->socket_id);
   if (!socket) {
     error_ = kSocketNotFoundError;
     AsyncWorkCompleted();
     return;
   }
 
@@ skipping 253 matching lines @@
 
   int net_result = socket->SetBroadcast(params_->enabled);
   if (net_result != net::OK) {
     error_ = net::ErrorToString(net_result);
   }
   results_ = sockets_udp::SetBroadcast::Results::Create(net_result);
 }
 
 }  // namespace api
 }  // namespace extensions