Add support of IP_MULTICAST_IF in UDP sockets.

net/udp/udp_server_socket.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/udp/udp_server_socket.h"
 
 #include "net/base/rand_callback.h"
 
 namespace net {
 
@@ skipping 51 matching lines @@
 }
 
 void UDPServerSocket::AllowAddressReuse() {
   socket_.AllowAddressReuse();
 }
 
 void UDPServerSocket::AllowBroadcast() {
   socket_.AllowBroadcast();
 }
 
-int UDPServerSocket::JoinGroup(const IPAddressNumber& group_address) const {
+int UDPServerSocket::SetMulticastInterface(uint32 interface_index) {
+  return socket_.SetMulticastInterface(interface_index);
+}
+
+int UDPServerSocket::JoinGroup(const IPAddressNumber& group_address) {
   return socket_.JoinGroup(group_address);
 }
 
-int UDPServerSocket::LeaveGroup(const IPAddressNumber& group_address) const {
+int UDPServerSocket::LeaveGroup(const IPAddressNumber& group_address) {
   return socket_.LeaveGroup(group_address);
 }
 
 int UDPServerSocket::SetMulticastTimeToLive(int time_to_live) {
   return socket_.SetMulticastTimeToLive(time_to_live);
 }
 
 int UDPServerSocket::SetMulticastLoopbackMode(bool loopback) {
   return socket_.SetMulticastLoopbackMode(loopback);
 }
 
 int UDPServerSocket::SetDiffServCodePoint(DiffServCodePoint dscp) {
   return socket_.SetDiffServCodePoint(dscp);
 }
 
 }  // namespace net