Refactor tcp socket and unix domain socket.

net/socket/server_socket.h

Index: net/socket/server_socket.h
diff --git a/net/socket/server_socket.h b/net/socket/server_socket.h
index 11151eea1539636928b64aee65876dfacd9e60ec..9f87eea2d092ebe37e5d2c6fed0d2b68fd576ceb 100644
--- a/net/socket/server_socket.h
+++ b/net/socket/server_socket.h
@@ -5,6 +5,8 @@
 #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"
@@ -16,17 +18,25 @@ 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;