Move PostTaskAndReplyWithResult() adapters to a separate header.

base/BUILD.gn

 # Copyright (c) 2013 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.
 
 # HOW TO WRITE CONDITIONALS IN THIS FILE
 # ======================================
 #
 # In many other places, one would write a conditional that expresses all the
 # cases when a source file is used or unused, and then either add or subtract
 # it from the sources list in that case
@@ skipping 598 matching lines @@
     "pickle.cc",
     "pickle.h",
     "posix/eintr_wrapper.h",
     "posix/file_descriptor_shuffle.cc",
     "posix/global_descriptors.cc",
     "posix/global_descriptors.h",
     "posix/safe_strerror.cc",
     "posix/safe_strerror.h",
     "posix/unix_domain_socket_linux.cc",
     "posix/unix_domain_socket_linux.h",
+    "post_task_and_reply_with_result_internal.h",
     "power_monitor/power_monitor.cc",
     "power_monitor/power_monitor.h",
     "power_monitor/power_monitor_device_source.cc",
     "power_monitor/power_monitor_device_source.h",
     "power_monitor/power_monitor_source.cc",
     "power_monitor/power_monitor_source.h",
     "power_monitor/power_observer.h",
     "process/internal_linux.cc",
     "process/internal_linux.h",
     "process/kill.cc",
@@ skipping 1896 matching lines @@
 }
 
 fuzzer_test("base_json_correctness_fuzzer") {
   sources = [
     "json/correctness_fuzzer.cc",
   ]
   deps = [
     ":base",
   ]
 }