Adds a method to TCPServerSocket to adopt a socket.

net/socket/tcp_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_TCP_SERVER_SOCKET_H_
 #define NET_SOCKET_TCP_SERVER_SOCKET_H_
 
 #include <memory>
 
 #include "base/macros.h"
 #include "net/base/ip_endpoint.h"
 #include "net/base/net_export.h"
 #include "net/socket/server_socket.h"
+#include "net/socket/socket_descriptor.h"
 #include "net/socket/tcp_socket.h"
 
 namespace net {
 
 class NetLog;
 struct NetLogSource;
 
 // A server socket that uses TCP as the transport layer.
 class NET_EXPORT TCPServerSocket : public ServerSocket {
  public:
   TCPServerSocket(NetLog* net_log, const NetLogSource& source);
   ~TCPServerSocket() override;
 
+  // Takes ownership of |socket|, which has been opened, but may or may not be
+  // bound or listening. The caller must determine this based on the provenance
+  // of the socket and act accordingly. The socket may have connections waiting
+  // to be accepted, but must not be actually connected.
+  int AdoptSocket(SocketDescriptor socket);
+
   // net::ServerSocket implementation.
   int Listen(const IPEndPoint& address, int backlog) override;
   int GetLocalAddress(IPEndPoint* address) const override;
   int Accept(std::unique_ptr<StreamSocket>* socket,
              const CompletionCallback& callback) override;
 
   // Detachs from the current thread, to allow the socket to be transferred to
   // a new thread. Should only be called when the object is no longer used by
   // the old thread.
   void DetachFromThread();
@@ skipping 16 matching lines @@
   std::unique_ptr<TCPSocket> accepted_socket_;
   IPEndPoint accepted_address_;
   bool pending_accept_;
 
   DISALLOW_COPY_AND_ASSIGN(TCPServerSocket);
 };
 
 }  // namespace net
 
 #endif  // NET_SOCKET_TCP_SERVER_SOCKET_H_