Mojo C++ bindings: remove the utility/ folder.

mojo/public/cpp/utility/lib/thread_local_posix.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 "mojo/public/cpp/utility/lib/thread_local.h"
-
-#include <assert.h>
-
-namespace mojo {
-namespace internal {
-
-// static
-void ThreadLocalPlatform::AllocateSlot(SlotType* slot) {
-  if (pthread_key_create(slot, nullptr) != 0) {
-    assert(false);
-  }
-}
-
-// static
-void ThreadLocalPlatform::FreeSlot(SlotType slot) {
-  if (pthread_key_delete(slot) != 0) {
-    assert(false);
-  }
-}
-
-// static
-void* ThreadLocalPlatform::GetValueFromSlot(SlotType slot) {
-  return pthread_getspecific(slot);
-}
-
-// static
-void ThreadLocalPlatform::SetValueInSlot(SlotType slot, void* value) {
-  if (pthread_setspecific(slot, value) != 0) {
-    assert(false);
-  }
-}
-
-}  // namespace internal
-}  // namespace mojo