Refactor tcp socket and unix domain socket.

net/socket/server_socket.h

 // Copyright (c) 2011 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.
 
 #ifndef NET_SOCKET_SERVER_SOCKET_H_
 #define NET_SOCKET_SERVER_SOCKET_H_
 
+#include <string>
+
 #include "base/memory/scoped_ptr.h"
 #include "net/base/completion_callback.h"
 #include "net/base/net_export.h"
 
 namespace net {
 
 class IPEndPoint;
 class StreamSocket;
 
 class NET_EXPORT ServerSocket {
  public:
-  ServerSocket() { }
-  virtual ~ServerSocket() { }
+  ServerSocket();
+  virtual ~ServerSocket();
 
-  // Bind the socket and start listening. Destroy the socket to stop
+  // Binds the socket and starts listening. Destroy the socket to stop
   // listening.
   virtual int Listen(const net::IPEndPoint& address, int backlog) = 0;
 
+  // Binds the socket with address and port, and starts listening. It expects
+  // a valid IPv4 or IPv6 address. Otherwise, it returns ERR_ADDRESS_INVALID.
+  // Subclasses may override this function if |address_string| is in a different
+  // format, for example, unix domain socket path.
+  virtual int ListenWithAddressAndPort(const std::string& address_string,
+                                       int port,
+                                       int backlog);
+
   // Gets current address the socket is bound to.
   virtual int GetLocalAddress(IPEndPoint* address) const = 0;
 
-  // Accept connection. Callback is called when new connection is
+  // Accepts connection. Callback is called when new connection is
   // accepted.
   virtual int Accept(scoped_ptr<StreamSocket>* socket,
                      const CompletionCallback& callback) = 0;
 
  private:
   DISALLOW_COPY_AND_ASSIGN(ServerSocket);
 };
 
 }  // namespace net
 
 #endif  // NET_SOCKET_SERVER_SOCKET_H_