Adds a method to TCPServerSocket to adopt a socket.

net/socket/tcp_server_socket.h

Index: net/socket/tcp_server_socket.h
diff --git a/net/socket/tcp_server_socket.h b/net/socket/tcp_server_socket.h
index 3b4a9616ede4bdbe921ab63f7f5a627ec70b1231..a4a5c05397ca84570546e8ee19e04c1a2379b18a 100644
--- a/net/socket/tcp_server_socket.h
+++ b/net/socket/tcp_server_socket.h
@@ -11,6 +11,7 @@
 #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 {
@@ -24,6 +25,11 @@ class NET_EXPORT TCPServerSocket : public ServerSocket {
   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.
+  int AdoptUnconnectedSocket(SocketDescriptor socket);

[mmenke, 2017/04/21 19:20:38]

This works for connected sockets, too, right?  Maybe just AdoptSocket?

[Raul Vera, 2017/05/01 05:35:25]

It doesn't work for connected sockets, as the peer address will not get set
properly. The idea is that the server code will subsequently call Accept, which
will set the peer address.

However, in the case of a server only an unconnected socket makes sense so it
doesn't matter much. I've changed the name to what you suggest and added a
comment that it should not be connected.

+
   // net::ServerSocket implementation.
   int Listen(const IPEndPoint& address, int backlog) override;
   int GetLocalAddress(IPEndPoint* address) const override;