include what you use: errno.h in tools/android/

tools/android/forwarder2/socket.cc

 // Copyright (c) 2012 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.
 
 #include "tools/android/forwarder2/socket.h"
 
 #include <arpa/inet.h>
+#include <errno.h>
 #include <fcntl.h>
 #include <netdb.h>
 #include <netinet/in.h>
 #include <stdio.h>
 #include <string.h>
 #include <sys/socket.h>
 #include <sys/types.h>
 #include <unistd.h>
 
 #include "base/logging.h"
@@ skipping 422 matching lines @@
   ucred ucred;
   socklen_t len = sizeof(ucred);
   if (getsockopt(socket.socket_, SOL_SOCKET, SO_PEERCRED, &ucred, &len) == -1) {
     CHECK_NE(ENOPROTOOPT, errno);
     return -1;
   }
   return ucred.pid;
 }
 
 }  // namespace forwarder2