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

native_client_sdk/src/libraries/nacl_io/kernel_intercept.h

 /* 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.
  */
 #ifndef LIBRARIES_NACL_IO_KERNEL_INTERCEPT_H_
 #define LIBRARIES_NACL_IO_KERNEL_INTERCEPT_H_
 
 #include <ppapi/c/ppb.h>
 #include <ppapi/c/pp_instance.h>
 #include "nacl_io/ostypes.h"
-#include "utils/macros.h"
+#include "sdk_util/macros.h"
 
 EXTERN_C_BEGIN
 
 // The kernel intercept module provides a C->C++ thunk between the libc
 // kernel calls and the KernelProxy singleton.
 
 // ki_init must be called with an uninitialized KernelProxy object.  Calling
 // with NULL will instantiate a default kernel proxy object.  ki_init must
 // be called before any other ki_XXX function can be used.
 void ki_init(void* kernel_proxy);
@@ skipping 32 matching lines @@
 int ki_symlink(const char* oldpath, const char* newpath);
 void* ki_mmap(void* addr, size_t length, int prot, int flags, int fd,
               off_t offset);
 int ki_munmap(void* addr, size_t length);
 int ki_open_resource(const char* file);
 
 EXTERN_C_END
 
 #endif  // LIBRARIES_NACL_IO_KERNEL_INTERCEPT_H_