Add support of IP_MULTICAST_IF in UDP sockets.

net/udp/udp_server_socket.h

Index: net/udp/udp_server_socket.h
diff --git a/net/udp/udp_server_socket.h b/net/udp/udp_server_socket.h
index 6586f7e3c7281559554622eed1a87989ba6d317e..c3cc4621241e5db8bcfc19ff173b20dbefaa1665 100644
--- a/net/udp/udp_server_socket.h
+++ b/net/udp/udp_server_socket.h
@@ -18,8 +18,7 @@ class BoundNetLog;
 // A client socket that uses UDP as the transport layer.
 class NET_EXPORT UDPServerSocket : public DatagramServerSocket {
  public:
-  UDPServerSocket(net::NetLog* net_log,
-                  const net::NetLog::Source& source);
+  UDPServerSocket(net::NetLog* net_log, const net::NetLog::Source& source);
   virtual ~UDPServerSocket();
 
   // Implement DatagramServerSocket:
@@ -40,8 +39,9 @@ class NET_EXPORT UDPServerSocket : public DatagramServerSocket {
   virtual const BoundNetLog& NetLog() const OVERRIDE;
   virtual void AllowAddressReuse() OVERRIDE;
   virtual void AllowBroadcast() OVERRIDE;
-  virtual int JoinGroup(const IPAddressNumber& group_address) const OVERRIDE;
-  virtual int LeaveGroup(const IPAddressNumber& group_address) const OVERRIDE;
+  virtual int SetMulticastInterface(uint32 interface_index) OVERRIDE;
+  virtual int JoinGroup(const IPAddressNumber& group_address) OVERRIDE;
+  virtual int LeaveGroup(const IPAddressNumber& group_address) OVERRIDE;
   virtual int SetMulticastTimeToLive(int time_to_live) OVERRIDE;
   virtual int SetMulticastLoopbackMode(bool loopback) OVERRIDE;
   virtual int SetDiffServCodePoint(DiffServCodePoint dscp) OVERRIDE;