On Windows, the return value of socket() should be compared with

net/socket/tcp_server_socket_win.cc

Index: net/socket/tcp_server_socket_win.cc
===================================================================
--- net/socket/tcp_server_socket_win.cc	(revision 215189)
+++ net/socket/tcp_server_socket_win.cc	(working copy)
@@ -45,7 +45,7 @@
   }
 
   socket_ = socket(address.GetSockAddrFamily(), SOCK_STREAM, IPPROTO_TCP);
-  if (socket_ < 0) {
+  if (socket_ == INVALID_SOCKET) {

[wtc, 2013/08/12 17:31:30]

See the "Return value" section and example code in
http://msdn.microsoft.com/en-us/library/windows/desktop/ms740506%28v=vs.85%29...

     PLOG(ERROR) << "socket() returned an error";
     return MapSystemError(WSAGetLastError());
   }