Update from https://crrev.com/311076

net/dns/mdns_client_impl.cc

Index: net/dns/mdns_client_impl.cc
diff --git a/net/dns/mdns_client_impl.cc b/net/dns/mdns_client_impl.cc
index 622bca939e94d0585404d67340c431bf6faf7678..66873abc36bca278a33e0194f0dd85ae52f91740 100644
--- a/net/dns/mdns_client_impl.cc
+++ b/net/dns/mdns_client_impl.cc
@@ -195,8 +195,7 @@ void MDnsConnection::OnDatagramReceived(
   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() {
@@ -424,7 +423,7 @@ 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;