Include What You Use: #include <errno.h> where errno is used, or use DPLOG

rlz/lib/recursive_cross_process_lock_posix.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 "rlz/lib/recursive_cross_process_lock_posix.h"
 
+#include <errno.h>
 #include <fcntl.h>
 #include <sys/file.h>
 #include <sys/stat.h>
 #include <sys/types.h>
 #include <unistd.h>
 
 #include "base/files/file_path.h"
 #include "base/logging.h"
 #include "base/posix/eintr_wrapper.h"
 
@@ skipping 56 matching lines @@
     ignore_result(HANDLE_EINTR(flock(file_lock_, LOCK_UN)));
     ignore_result(HANDLE_EINTR(close(file_lock_)));
     file_lock_ = -1;
   }
 
   locking_thread_ = 0;
   pthread_mutex_unlock(&recursive_lock_);
 }
 
 }  // namespace rlz_lib