Allow server sockets to rebind to same port if there is nothing actively listening on that port.

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 "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() { }
 
+  // Allows the socket to share the local address to which the socket will be
+  // bound with other processes. Should be called before Listen().
+  virtual void AllowAddressReuse();

[wtc, 2012/09/14 19:20:17]

This should be a pure virtual method, with = 0.

[justinlin, 2012/09/15 19:03:25]

Done.

+
   // Bind the socket and start listening. Destroy the socket to stop
   // listening.
   virtual int Listen(const net::IPEndPoint& address, int backlog) = 0;
 
   // Gets current address the socket is bound to.
   virtual int GetLocalAddress(IPEndPoint* address) const = 0;
 
   // Accept 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_