Update from https://crrev.com/311076

net/dns/mdns_client_impl.cc

 // Copyright 2013 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/dns/mdns_client_impl.h"
 
 #include <queue>
 
 #include "base/bind.h"
 #include "base/message_loop/message_loop_proxy.h"
@@ skipping 177 matching lines @@
 
 void MDnsConnection::OnDatagramReceived(
     DnsResponse* response,
     const IPEndPoint& recv_addr,
     int bytes_read) {
   // TODO(noamsml): More sophisticated error handling.
   DCHECK_GT(bytes_read, 0);
   delegate_->HandlePacket(response, bytes_read);
 }
 
-MDnsClientImpl::Core::Core(MDnsClientImpl* client)
-    : client_(client), connection_(new MDnsConnection(this)) {
+MDnsClientImpl::Core::Core() : connection_(new MDnsConnection(this)) {
 }
 
 MDnsClientImpl::Core::~Core() {
   STLDeleteValues(&listeners_);
 }
 
 bool MDnsClientImpl::Core::Init(MDnsSocketFactory* socket_factory) {
   return connection_->Init(socket_factory);
 }
 
@@ skipping 207 matching lines @@
 }
 
 MDnsClientImpl::MDnsClientImpl() {
 }
 
 MDnsClientImpl::~MDnsClientImpl() {
 }
 
 bool MDnsClientImpl::StartListening(MDnsSocketFactory* socket_factory) {
   DCHECK(!core_.get());
-  core_.reset(new Core(this));
+  core_.reset(new Core());
   if (!core_->Init(socket_factory)) {
     core_.reset();
     return false;
   }
   return true;
 }
 
 void MDnsClientImpl::StopListening() {
   core_.reset();
 }
@@ skipping 289 matching lines @@
 
 void MDnsTransactionImpl::OnNsecRecord(const std::string& name, unsigned type) {
   TriggerCallback(RESULT_NSEC, NULL);
 }
 
 void MDnsTransactionImpl::OnCachePurged() {
   // TODO(noamsml): Cache purge situations not yet implemented
 }
 
 }  // namespace net