Introduce a SchedulerHelper in content/child/scheduler

content/child/scheduler/task_queue_manager.h

Index: content/child/scheduler/task_queue_manager.h
diff --git a/content/renderer/scheduler/task_queue_manager.h b/content/child/scheduler/task_queue_manager.h
similarity index 98%
rename from content/renderer/scheduler/task_queue_manager.h
rename to content/child/scheduler/task_queue_manager.h
index ae38cc8be5db6596f959c7ac5d397160ae769f33..95876f14fc13aaeb0463edec575331b3dca255fe 100644
--- a/content/renderer/scheduler/task_queue_manager.h
+++ b/content/child/scheduler/task_queue_manager.h
@@ -73,7 +73,8 @@ class CONTENT_EXPORT TaskQueueManager {
   TaskQueueManager(
       size_t task_queue_count,
       scoped_refptr<NestableSingleThreadTaskRunner> main_task_runner,
-      TaskQueueSelector* selector);
+      TaskQueueSelector* selector,
+      const char* disabled_by_default_tracing_category);
   ~TaskQueueManager();
 
   // Returns the task runner which targets the queue selected by |queue_index|.
@@ -194,6 +195,8 @@ class CONTENT_EXPORT TaskQueueManager {
 
   ObserverList<base::MessageLoop::TaskObserver> task_observers_;
 
+  const char* disabled_by_default_tracing_category_;
+
   base::WeakPtrFactory<TaskQueueManager> weak_factory_;
 
   DISALLOW_COPY_AND_ASSIGN(TaskQueueManager);