[Try # 3] Scheduler refactoring to virtually eliminate redundant DoWorks

third_party/WebKit/Source/platform/scheduler/child/scheduler_helper.cc

Index: third_party/WebKit/Source/platform/scheduler/child/scheduler_helper.cc
diff --git a/third_party/WebKit/Source/platform/scheduler/child/scheduler_helper.cc b/third_party/WebKit/Source/platform/scheduler/child/scheduler_helper.cc
index f33bffaae49ef0ce5fa2f3b9654fbb1ff54412e6..6d455de38197232e8bcfbddd451adc5adb22cf6c 100644
--- a/third_party/WebKit/Source/platform/scheduler/child/scheduler_helper.cc
+++ b/third_party/WebKit/Source/platform/scheduler/child/scheduler_helper.cc
@@ -18,6 +18,19 @@ SchedulerHelper::SchedulerHelper(
     const char* tracing_category,
     const char* disabled_by_default_tracing_category,
     const char* disabled_by_default_verbose_tracing_category)
+    : SchedulerHelper(task_queue_manager_delegate,
+                      tracing_category,
+                      disabled_by_default_tracing_category,
+                      disabled_by_default_verbose_tracing_category,
+                      TaskQueue::Spec(TaskQueue::QueueType::DEFAULT)
+                          .SetShouldMonitorQuiescence(true)) {}
+
+SchedulerHelper::SchedulerHelper(
+    scoped_refptr<SchedulerTqmDelegate> task_queue_manager_delegate,
+    const char* tracing_category,
+    const char* disabled_by_default_tracing_category,
+    const char* disabled_by_default_verbose_tracing_category,
+    TaskQueue::Spec default_task_queue_spec)
     : task_queue_manager_delegate_(task_queue_manager_delegate),
       task_queue_manager_(
           new TaskQueueManager(task_queue_manager_delegate,
@@ -27,9 +40,7 @@ SchedulerHelper::SchedulerHelper(
       control_task_runner_(
           NewTaskQueue(TaskQueue::Spec(TaskQueue::QueueType::CONTROL)
                            .SetShouldNotifyObservers(false))),
-      default_task_runner_(
-          NewTaskQueue(TaskQueue::Spec(TaskQueue::QueueType::DEFAULT)
-                           .SetShouldMonitorQuiescence(true))),
+      default_task_runner_(NewTaskQueue(default_task_queue_spec)),
       observer_(nullptr),
       tracing_category_(tracing_category),
       disabled_by_default_tracing_category_(
@@ -55,6 +66,15 @@ void SchedulerHelper::Shutdown() {
   task_queue_manager_delegate_->RestoreDefaultTaskRunner();
 }
 
+void SchedulerHelper::SetRecordTaskDelayHistograms(
+    bool record_task_delay_histograms) {
+  if (!task_queue_manager_)
+    return;
+
+  task_queue_manager_->SetRecordTaskDelayHistograms(
+      record_task_delay_histograms);
+}
+
 scoped_refptr<TaskQueue> SchedulerHelper::NewTaskQueue(
     const TaskQueue::Spec& spec) {
   DCHECK(task_queue_manager_.get());
@@ -136,8 +156,8 @@ void SchedulerHelper::SweepCanceledDelayedTasks() {
 }
 
 RealTimeDomain* SchedulerHelper::real_time_domain() const {
-  CheckOnValidThread();
-  DCHECK(task_queue_manager_);
+  if (!task_queue_manager_)
+    return nullptr;
   return task_queue_manager_->real_time_domain();
 }