Revert of Revert of Add a WorkerScheduler and a WebThreadImplForWorker

content/child/scheduler/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/worker_scheduler.h"
+
+#include "base/command_line.h"
+#include "base/message_loop/message_loop.h"
+#include "content/child/scheduler/null_worker_scheduler.h"
+#include "content/child/scheduler/scheduler_message_loop_delegate.h"
+#include "content/child/scheduler/worker_scheduler_impl.h"
+#include "content/public/common/content_switches.h"
+
+namespace content {
+
+WorkerScheduler::WorkerScheduler() {
+}
+
+WorkerScheduler::~WorkerScheduler() {
+}
+
+// static
+scoped_ptr<WorkerScheduler> WorkerScheduler::Create(
+    base::MessageLoop* message_loop) {
+  base::CommandLine* command_line = base::CommandLine::ForCurrentProcess();
+  if (command_line->HasSwitch(switches::kDisableBlinkScheduler)) {
+    return make_scoped_ptr(new NullWorkerScheduler());
+  } else {
+    return make_scoped_ptr(new WorkerSchedulerImpl(
+        SchedulerMessageLoopDelegate::Create(message_loop)));
+  }
+}
+
+}  // namespace content