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

native_client_sdk/src/libraries/nacl_io/mount_html5fs.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 "nacl_io/mount_html5fs.h"
 
 #include <errno.h>
 #include <ppapi/c/pp_completion_callback.h>
 #include <ppapi/c/pp_errors.h>
 #include <stdlib.h>
 #include <string.h>
 #include <algorithm>
 #include "nacl_io/mount_node_html5fs.h"
-#include "utils/auto_lock.h"
+#include "sdk_util/auto_lock.h"
 
 namespace {
 
 #if defined(WIN32)
 int64_t strtoull(const char* nptr, char** endptr, int base) {
   return _strtoui64(nptr, endptr, base);
 }
 #endif
 
 }  // namespace
@@ skipping 157 matching lines @@
   MountHtml5Fs* self = static_cast<MountHtml5Fs*>(user_data);
   self->FilesystemOpenCallback(result);
 }
 
 void MountHtml5Fs::FilesystemOpenCallback(int32_t result) {
   AutoLock lock(&lock_);
   filesystem_open_has_result_ = true;
   filesystem_open_result_ = result;
   pthread_cond_signal(&filesystem_open_cond_);
 }