Adds a method to TCPServerSocket to adopt a socket.

net/socket/tcp_socket_posix.cc

Index: net/socket/tcp_socket_posix.cc
diff --git a/net/socket/tcp_socket_posix.cc b/net/socket/tcp_socket_posix.cc
index 82f42a72c0803f095e32bb08f60ca55601c3a73e..51e8b9c3dd24ab5cf9d212215e66ce310644a6b0 100644
--- a/net/socket/tcp_socket_posix.cc
+++ b/net/socket/tcp_socket_posix.cc
@@ -175,7 +175,7 @@ int TCPSocketPosix::Open(AddressFamily family) {
   return rv;
 }
 
-int TCPSocketPosix::AdoptConnectedSocket(int socket_fd,
+int TCPSocketPosix::AdoptConnectedSocket(SocketDescriptor socket,
                                          const IPEndPoint& peer_address) {
   DCHECK(!socket_);
 
@@ -187,7 +187,17 @@ int TCPSocketPosix::AdoptConnectedSocket(int socket_fd,
   }
 
   socket_.reset(new SocketPosix);
-  int rv = socket_->AdoptConnectedSocket(socket_fd, storage);
+  int rv = socket_->AdoptConnectedSocket(socket, storage);
+  if (rv != OK)
+    socket_.reset();
+  return rv;
+}
+
+int TCPSocketPosix::AdoptUnconnectedSocket(SocketDescriptor socket) {
+  DCHECK(!socket_);
+
+  socket_.reset(new SocketPosix);
+  int rv = socket_->AdoptUnconnectedSocket(socket);
   if (rv != OK)
     socket_.reset();
   return rv;
@@ -485,6 +495,12 @@ void TCPSocketPosix::EndLoggingMultipleConnectAttempts(int net_error) {
   }
 }
 
+SocketDescriptor TCPSocketPosix::ReleaseSocketDescriptorForTesting() {
+  SocketDescriptor socket_descriptor = socket_->ReleaseConnectedSocket();
+  socket_.reset();
+  return socket_descriptor;
+}
+
 void TCPSocketPosix::AcceptCompleted(
     std::unique_ptr<TCPSocketPosix>* tcp_socket,
     IPEndPoint* address,