Revert of Worker: Introduce per-global-scope task scheduler

third_party/WebKit/Source/platform/scheduler/child/worker_scheduler.h

Index: third_party/WebKit/Source/platform/scheduler/child/worker_scheduler.h
diff --git a/third_party/WebKit/Source/platform/scheduler/child/worker_scheduler.h b/third_party/WebKit/Source/platform/scheduler/child/worker_scheduler.h
index 6ecca6daa22d7b98ffc4a434b3071afe10f95ea6..5fc53ec067042b450e4ca95a8970bd522282d78c 100644
--- a/third_party/WebKit/Source/platform/scheduler/child/worker_scheduler.h
+++ b/third_party/WebKit/Source/platform/scheduler/child/worker_scheduler.h
@@ -9,9 +9,7 @@
 
 #include "base/macros.h"
 #include "base/message_loop/message_loop.h"
-#include "platform/scheduler/child/scheduler_helper.h"
 #include "public/platform/WebCommon.h"
-#include "public/platform/scheduler/base/task_queue.h"
 #include "public/platform/scheduler/child/child_scheduler.h"
 #include "public/platform/scheduler/child/single_thread_idle_task_runner.h"
 
@@ -29,14 +27,8 @@
   // initialization needed such as initializing idle period detection.
   virtual void Init() = 0;
 
-  scoped_refptr<TaskQueue> CreateUnthrottledTaskRunner(
-      TaskQueue::QueueType queue_type);
-
  protected:
-  explicit WorkerScheduler(std::unique_ptr<SchedulerHelper> helper);
-
-  std::unique_ptr<SchedulerHelper> helper_;
-
+  WorkerScheduler();
   DISALLOW_COPY_AND_ASSIGN(WorkerScheduler);
 };