Revert of Adds TimeDomains to the TaskQueueManager

components/scheduler/child/scheduler_helper.cc

Index: components/scheduler/child/scheduler_helper.cc
diff --git a/components/scheduler/child/scheduler_helper.cc b/components/scheduler/child/scheduler_helper.cc
index f4081fde958130a00da733500bc63f0b8f37256c..9056e2bb2c8421093e4902751dee21ff2336f120 100644
--- a/components/scheduler/child/scheduler_helper.cc
+++ b/components/scheduler/child/scheduler_helper.cc
@@ -96,6 +96,11 @@
   return task_queue_manager_delegate_;
 }
 
+base::TimeTicks SchedulerHelper::NextPendingDelayedTaskRunTime() const {
+  CheckOnValidThread();
+  DCHECK(task_queue_manager_.get());
+  return task_queue_manager_->NextPendingDelayedTaskRunTime();
+}
 
 bool SchedulerHelper::GetAndClearSystemIsQuiescentBit() {
   CheckOnValidThread();
@@ -130,10 +135,4 @@
     observer_->OnUnregisterTaskQueue(queue);
 }
 
-const scoped_refptr<RealTimeDomain>& SchedulerHelper::real_time_domain() const {
-  CheckOnValidThread();
-  DCHECK(task_queue_manager_);
-  return task_queue_manager_->real_time_domain();
-}
-
 }  // namespace scheduler