include what you use: errno.h in sandbox/

sandbox/linux/services/yama.cc

 // 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.
 
 #include "sandbox/linux/services/yama.h"
 
+#include <errno.h>
 #include <fcntl.h>
 #include <sys/prctl.h>
 #include <sys/stat.h>
 #include <sys/types.h>
 #include <unistd.h>
 
 #include "base/files/file_util.h"
 #include "base/files/scoped_file.h"
 #include "base/logging.h"
 #include "base/posix/eintr_wrapper.h"
@@ skipping 89 matching lines @@
   }
 }
 
 // static
 bool Yama::IsPresent() { return GetStatus() & STATUS_PRESENT; }
 
 // static
 bool Yama::IsEnforcing() { return GetStatus() & STATUS_ENFORCING; }
 
 }  // namespace sandbox