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

net/socket/tcp_server_socket_libevent.h

Index: net/socket/tcp_server_socket_libevent.h
diff --git a/net/socket/tcp_server_socket_libevent.h b/net/socket/tcp_server_socket_libevent.h
index 946cc50f949d56911d0a0a437a0c02b3dfd95165..3b8d71ecebb6e0d10bfb81aef564f213b7e5868c 100644
--- a/net/socket/tcp_server_socket_libevent.h
+++ b/net/socket/tcp_server_socket_libevent.h
@@ -26,6 +26,7 @@ class NET_EXPORT_PRIVATE TCPServerSocketLibevent
   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,
@@ -36,6 +37,7 @@ class NET_EXPORT_PRIVATE TCPServerSocketLibevent
   virtual void OnFileCanWriteWithoutBlocking(int fd) OVERRIDE;
 
  private:
+  int SetSocketOptions();
   int AcceptInternal(scoped_ptr<StreamSocket>* socket);
   void Close();
 
@@ -46,6 +48,8 @@ class NET_EXPORT_PRIVATE TCPServerSocketLibevent
   scoped_ptr<StreamSocket>* accept_socket_;
   CompletionCallback accept_callback_;
 
+  bool reuse_address_;
+
   BoundNetLog net_log_;
 };