Move thread_pool.h into utils so it can be shared by more than one example.

native_client_sdk/src/libraries/nacl_io/mount_dev.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.
  */
 #if defined(WIN32)
 #define _CRT_RAND_S
 #endif
 
 #include <errno.h>
 #include <fcntl.h>
 #include <string.h>
 #include "nacl_io/kernel_wrap_real.h"
 #include "nacl_io/mount_dev.h"
 #include "nacl_io/mount_node.h"
 #include "nacl_io/mount_node_dir.h"
 #include "nacl_io/pepper_interface.h"
-#include "utils/auto_lock.h"
+#include "sdk_util/auto_lock.h"
 
 #if defined(__native_client__)
 #  include <irt.h>
 #elif defined(WIN32)
 #  include <stdlib.h>
 #endif
 
 
 namespace {
 
@@ skipping 306 matching lines @@
   ReleaseAndNullNode(&tty_node_);
   ReleaseAndNullNode(&console3_node_);
   ReleaseAndNullNode(&console2_node_);
   ReleaseAndNullNode(&console1_node_);
   ReleaseAndNullNode(&console0_node_);
   ReleaseAndNullNode(&random_node_);
   ReleaseAndNullNode(&zero_node_);
   ReleaseAndNullNode(&null_node_);
   ReleaseAndNullNode(&root_);
 }