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

net/socket/tcp_server_socket_libevent.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_TCP_SERVER_SOCKET_LIBEVENT_H_
 #define NET_SOCKET_TCP_SERVER_SOCKET_LIBEVENT_H_
 
 #include "base/memory/scoped_ptr.h"
 #include "base/message_loop.h"
 #include "base/threading/non_thread_safe.h"
 #include "net/base/completion_callback.h"
 #include "net/base/net_log.h"
 #include "net/socket/server_socket.h"
 
 namespace net {
 
 class IPEndPoint;
 
 class NET_EXPORT_PRIVATE TCPServerSocketLibevent
     : public ServerSocket,
       public base::NonThreadSafe,
       public MessageLoopForIO::Watcher {
  public:
   TCPServerSocketLibevent(net::NetLog* net_log,
                           const net::NetLog::Source& source);
   virtual ~TCPServerSocketLibevent();
 
   // net::ServerSocket implementation.
+  virtual void AllowAddressReuse() OVERRIDE;
   virtual int Listen(const net::IPEndPoint& address, int backlog) OVERRIDE;
   virtual int GetLocalAddress(IPEndPoint* address) const OVERRIDE;
   virtual int Accept(scoped_ptr<StreamSocket>* socket,
                      const CompletionCallback& callback) OVERRIDE;
 
   // MessageLoopForIO::Watcher implementation.
   virtual void OnFileCanReadWithoutBlocking(int fd) OVERRIDE;
   virtual void OnFileCanWriteWithoutBlocking(int fd) OVERRIDE;
 
  private:
+  int SetSocketOptions();
   int AcceptInternal(scoped_ptr<StreamSocket>* socket);
   void Close();
 
   int socket_;
 
   MessageLoopForIO::FileDescriptorWatcher accept_socket_watcher_;
 
   scoped_ptr<StreamSocket>* accept_socket_;
   CompletionCallback accept_callback_;
 
+  bool reuse_address_;
+
   BoundNetLog net_log_;
 };
 
 }  // namespace net
 
 #endif  // NET_SOCKET_TCP_SERVER_SOCKET_LIBEVENT_H_