Revert of Add a WorkerScheduler and a WebThreadImplForWorker

content/child/scheduler/webthread_impl_for_worker_scheduler.cc

-// Copyright 2015 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 "content/child/scheduler/webthread_impl_for_worker_scheduler.h"
-
-#include "base/bind.h"
-#include "base/synchronization/waitable_event.h"
-#include "content/child/scheduler/scheduler_message_loop_delegate.h"
-#include "content/child/scheduler/worker_scheduler_impl.h"
-#include "third_party/WebKit/public/platform/WebTraceLocation.h"
-
-namespace content {
-
-WebThreadImplForWorkerScheduler::WebThreadImplForWorkerScheduler(
-    const char* name)
-    : thread_(new base::Thread(name)) {
-  thread_->Start();
-
-  base::WaitableEvent completion(false, false);
-  thread_->message_loop()->PostTask(
-      FROM_HERE, base::Bind(&WebThreadImplForWorkerScheduler::InitOnThread,
-                            base::Unretained(this), &completion));
-  completion.Wait();
-}
-
-WebThreadImplForWorkerScheduler::~WebThreadImplForWorkerScheduler() {
-  base::WaitableEvent completion(false, false);
-  // We need to post the shutdown task on the scheduler's task queue or tasks
-  // posted on the worker scheduler may not get run when the thread is deleted.
-  TaskRunner()->PostTask(
-      FROM_HERE, base::Bind(&WebThreadImplForWorkerScheduler::ShutDownOnThread,
-                            base::Unretained(this), &completion));
-  completion.Wait();
-
-  thread_->Stop();
-}
-
-void WebThreadImplForWorkerScheduler::InitOnThread(
-    base::WaitableEvent* completion) {
-  worker_scheduler_ = WorkerScheduler::Create(thread_->message_loop());
-  worker_scheduler_->Init();
-  task_runner_ = worker_scheduler_->DefaultTaskRunner();
-  idle_task_runner_ = worker_scheduler_->IdleTaskRunner();
-  completion->Signal();
-}
-
-void WebThreadImplForWorkerScheduler::ShutDownOnThread(
-    base::WaitableEvent* completion) {
-  task_runner_ = nullptr;
-  idle_task_runner_ = nullptr;
-  worker_scheduler_.reset(nullptr);
-  completion->Signal();
-}
-
-blink::PlatformThreadId WebThreadImplForWorkerScheduler::threadId() const {
-  return thread_->thread_id();
-}
-
-base::MessageLoop* WebThreadImplForWorkerScheduler::MessageLoop() const {
-  // As per WebThreadImpl::MessageLoop()
-  return nullptr;
-}
-
-base::SingleThreadTaskRunner* WebThreadImplForWorkerScheduler::TaskRunner()
-    const {
-  return task_runner_.get();
-}
-
-SingleThreadIdleTaskRunner* WebThreadImplForWorkerScheduler::IdleTaskRunner()
-    const {
-  return idle_task_runner_.get();
-}
-
-void WebThreadImplForWorkerScheduler::AddTaskObserverInternal(
-    base::MessageLoop::TaskObserver* observer) {
-  worker_scheduler_->AddTaskObserver(observer);
-}
-
-void WebThreadImplForWorkerScheduler::RemoveTaskObserverInternal(
-    base::MessageLoop::TaskObserver* observer) {
-  worker_scheduler_->RemoveTaskObserver(observer);
-}
-
-}  // namespace content