Adds a method to TCPServerSocket to adopt a socket.

net/socket/socket_posix.h

 // Copyright 2014 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_SOCKET_POSIX_H_
 #define NET_SOCKET_SOCKET_POSIX_H_
 
 #include <memory>
 
 #include "base/compiler_specific.h"
@@ skipping 13 matching lines @@
 // Socket class to provide asynchronous read/write operations on top of the
 // posix socket api. It supports AF_INET, AF_INET6, and AF_UNIX addresses.
 class NET_EXPORT_PRIVATE SocketPosix : public base::MessageLoopForIO::Watcher {
  public:
   SocketPosix();
   ~SocketPosix() override;
 
   // Opens a socket and returns net::OK if |address_family| is AF_INET, AF_INET6
   // or AF_UNIX. Otherwise, it does DCHECK() and returns a net error.
   int Open(int address_family);
-  // Takes ownership of |socket|.
+
+  // Takes ownership of |socket|, which is known to already be connected to the
+  // given peer address.
   int AdoptConnectedSocket(SocketDescriptor socket,
                            const SockaddrStorage& peer_address);
+  // Takes ownership of |socket|, which may or may not be open, bound, or
+  // listening. The caller must determine the state of the socket based on its
+  // provenance and act accordingly. The socket may have connections waiting
+  // to be accepted, but must not be actually connected.
+  int AdoptUnconnectedSocket(SocketDescriptor socket);
+
   // Releases ownership of |socket_fd_| to caller.
   SocketDescriptor ReleaseConnectedSocket();
 
   int Bind(const SockaddrStorage& address);
 
   int Listen(int backlog);
   int Accept(std::unique_ptr<SocketPosix>* socket,
              const CompletionCallback& callback);
 
   // Connects socket. On non-ERR_IO_PENDING error, sets errno and returns a net
@@ skipping 93 matching lines @@
   std::unique_ptr<SockaddrStorage> peer_address_;
 
   base::ThreadChecker thread_checker_;
 
   DISALLOW_COPY_AND_ASSIGN(SocketPosix);
 };
 
 }  // namespace net
 
 #endif  // NET_SOCKET_SOCKET_POSIX_H_