Report expected task queueing time via UMA

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 43944359e0497c0b997600f46f027efed3516ea1..64dbecc34f20e4f6ab83029ecc66a682dd77d04b 100644
--- a/components/scheduler/child/scheduler_helper.cc
+++ b/components/scheduler/child/scheduler_helper.cc
@@ -22,7 +22,8 @@ SchedulerHelper::SchedulerHelper(
           new TaskQueueManager(task_queue_manager_delegate,
                                tracing_category,
                                disabled_by_default_tracing_category,
-                               disabled_by_default_verbose_tracing_category)),
+                               disabled_by_default_verbose_tracing_category,
+                               &task_time_tracker_)),
       control_task_runner_(NewTaskQueue(
           TaskQueue::Spec("control_tq")
               .SetWakeupPolicy(TaskQueue::WakeupPolicy::DONT_WAKE_OTHER_QUEUES)
@@ -32,8 +33,8 @@ SchedulerHelper::SchedulerHelper(
               .SetPumpPolicy(TaskQueue::PumpPolicy::AFTER_WAKEUP)
               .SetWakeupPolicy(TaskQueue::WakeupPolicy::DONT_WAKE_OTHER_QUEUES)
               .SetShouldNotifyObservers(false))),
-      default_task_runner_(NewTaskQueue(TaskQueue::Spec("default_tq")
-                                            .SetShouldMonitorQuiescence(true))),
+      default_task_runner_(NewTaskQueue(
+          TaskQueue::Spec("default_tq").SetShouldMonitorQuiescence(true))),
       observer_(nullptr),
       tracing_category_(tracing_category),
       disabled_by_default_tracing_category_(
@@ -122,6 +123,7 @@ void SchedulerHelper::SetObserver(Observer* observer) {
   observer_ = observer;
   DCHECK(task_queue_manager_);
   task_queue_manager_->SetObserver(this);
+  task_time_tracker_.SetObserver(this);
 }
 
 RealTimeDomain* SchedulerHelper::real_time_domain() const {
@@ -161,4 +163,8 @@ TaskQueue* SchedulerHelper::CurrentlyExecutingTaskQueue() const {
   return task_queue_manager_->currently_executing_task_queue();
 }
 
+// TaskTimeTracker::TaskTimeObserver implementation:
+void SchedulerHelper::OnQueueingTimeForWindowEstimated(
+    base::TimeDelta queueing_time) {}
+
 }  // namespace scheduler