Remove base::mac::LibDispatchTaskRunner and migrate its sole client to plain libdispatch.

base/mac/libdispatch_task_runner.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 "base/mac/libdispatch_task_runner.h"
-
-#include <stdint.h>
-
-#include "base/callback.h"
-
-namespace base {
-namespace mac {
-
-LibDispatchTaskRunner::LibDispatchTaskRunner(const char* name)
-    : queue_(dispatch_queue_create(name, NULL)),
-      queue_finalized_(base::WaitableEvent::ResetPolicy::AUTOMATIC,
-                       base::WaitableEvent::InitialState::NOT_SIGNALED) {
-  dispatch_set_context(queue_, this);
-  dispatch_set_finalizer_f(queue_, &LibDispatchTaskRunner::Finalizer);
-}
-
-bool LibDispatchTaskRunner::PostDelayedTask(
-    const tracked_objects::Location& from_here,
-    const Closure& task,
-    base::TimeDelta delay) {
-  if (!queue_)
-    return false;
-
-  // The block runtime would implicitly copy the reference, not the object
-  // it's referencing. Copy the closure into block storage so it's available
-  // to run.
-  __block const Closure task_copy = task;
-  void(^run_task)(void) = ^{
-      task_copy.Run();
-  };
-
-  int64_t delay_nano =
-      delay.InMicroseconds() * base::Time::kNanosecondsPerMicrosecond;
-  if (delay_nano > 0) {
-    dispatch_time_t time = dispatch_time(DISPATCH_TIME_NOW, delay_nano);
-    dispatch_after(time, queue_, run_task);
-  } else {
-    dispatch_async(queue_, run_task);
-  }
-  return true;
-}
-
-bool LibDispatchTaskRunner::RunsTasksOnCurrentThread() const {
-  return queue_ == dispatch_get_current_queue();
-}
-
-bool LibDispatchTaskRunner::PostNonNestableDelayedTask(
-    const tracked_objects::Location& from_here,
-    const Closure& task,
-    base::TimeDelta delay) {
-  return PostDelayedTask(from_here, task, delay);
-}
-
-void LibDispatchTaskRunner::Shutdown() {
-  dispatch_release(queue_);
-  queue_ = NULL;
-  queue_finalized_.Wait();
-}
-
-dispatch_queue_t LibDispatchTaskRunner::GetDispatchQueue() const {
-  return queue_;
-}
-
-LibDispatchTaskRunner::~LibDispatchTaskRunner() {
-  if (queue_) {
-    dispatch_set_context(queue_, NULL);
-    dispatch_set_finalizer_f(queue_, NULL);
-    dispatch_release(queue_);
-  }
-}
-
-void LibDispatchTaskRunner::Finalizer(void* context) {
-  LibDispatchTaskRunner* self = static_cast<LibDispatchTaskRunner*>(context);
-  self->queue_finalized_.Signal();
-}
-
-}  // namespace mac
-}  // namespace base