Make the fuchsia mojo/public repo the source of truth.

mojo/public/platform/native/platform_handle_private_thunks.c

-// Copyright 2016 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/platform/native/platform_handle_private_thunks.h"
-
-#include "mojo/public/platform/native/thunk_export.h"
-
-#include <assert.h>
-
-static struct MojoPlatformHandlePrivateThunks g_thunks = {0};
-
-MojoResult MojoCreatePlatformHandleWrapper(
-    MojoPlatformHandle platform_handle,
-    MojoHandle* platform_handle_wrapper_handle) {
-  assert(g_thunks.CreatePlatformHandleWrapper);
-  return g_thunks.CreatePlatformHandleWrapper(platform_handle,
-                                              platform_handle_wrapper_handle);
-}
-
-MojoResult MojoExtractPlatformHandle(MojoHandle platform_handle_wrapper_handle,
-                                     MojoPlatformHandle* platform_handle) {
-  assert(g_thunks.ExtractPlatformHandle);
-  return g_thunks.ExtractPlatformHandle(platform_handle_wrapper_handle,
-                                        platform_handle);
-}
-
-THUNK_EXPORT size_t MojoSetPlatformHandlePrivateThunks(
-    const struct MojoPlatformHandlePrivateThunks* thunks) {
-  if (thunks->size >= sizeof(g_thunks))
-    g_thunks = *thunks;
-  return sizeof(g_thunks);
-}