scheduler: Implement task observers

content/renderer/scheduler/webthread_impl_for_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/renderer/scheduler/webthread_impl_for_scheduler.h"
+
+#include "content/renderer/scheduler/renderer_scheduler.h"
+#include "third_party/WebKit/public/platform/WebTraceLocation.h"
+
+namespace content {
+
+WebThreadImplForScheduler::WebThreadImplForScheduler(
+    RendererScheduler* scheduler)
+    : task_runner_(scheduler->DefaultTaskRunner()),
+      scheduler_(scheduler),
+      thread_id_(base::PlatformThread::CurrentId()) {
+}
+
+WebThreadImplForScheduler::~WebThreadImplForScheduler() {
+}
+
+blink::PlatformThreadId WebThreadImplForScheduler::threadId() const {
+  return thread_id_;
+}
+
+base::MessageLoop* WebThreadImplForScheduler::MessageLoop() const {
+  DCHECK(isCurrentThread());
+  return base::MessageLoop::current();
+}
+
+base::SingleThreadTaskRunner* WebThreadImplForScheduler::TaskRunner() const {
+  return task_runner_.get();
+}
+
+void WebThreadImplForScheduler::AddTaskObserverInternal(
+    base::MessageLoop::TaskObserver* observer) {
+  scheduler_->AddTaskObserver(observer);
+}
+
+void WebThreadImplForScheduler::RemoveTaskObserverInternal(
+    base::MessageLoop::TaskObserver* observer) {
+  scheduler_->RemoveTaskObserver(observer);
+}
+
+}  // namespace content