Add unistd.h include in a file using geteuid().

base/process/process_iterator_mac.cc

 // Copyright (c) 2013 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 "base/process/process_iterator.h"
 
 #include <errno.h>
 #include <sys/sysctl.h>
 #include <sys/types.h>
+#include <unistd.h>
 
 #include "base/logging.h"
 #include "base/strings/string_util.h"
 
 namespace base {
 
 ProcessIterator::ProcessIterator(const ProcessFilter* filter)
     : index_of_kinfo_proc_(0),
       filter_(filter) {
   // Get a snapshot of all of my processes (yes, as we loop it can go stale, but
@@ skipping 105 matching lines @@
   }
   return false;
 }
 
 bool NamedProcessIterator::IncludeEntry() {
   return (executable_name_ == entry().exe_file() &&
           ProcessIterator::IncludeEntry());
 }
 
 }  // namespace base