Reduce the number of delayed tasks on chromium run loop

components/scheduler/base/task_queue_manager.cc

 // Copyright 2014 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "components/scheduler/base/task_queue_manager.h"
 
 #include <queue>
 #include <set>
 
 #include "base/bind.h"
@@ skipping 25 matching lines @@
   DCHECK(delegate->RunsTasksOnCurrentThread());
   TRACE_EVENT_OBJECT_CREATED_WITH_ID(disabled_by_default_tracing_category,
                                      "TaskQueueManager", this);
   selector_.SetTaskQueueSelectorObserver(this);
 
   decrement_pending_and_do_work_closure_ =
       base::Bind(&TaskQueueManager::DoWork, weak_factory_.GetWeakPtr(), true);
   do_work_closure_ =
       base::Bind(&TaskQueueManager::DoWork, weak_factory_.GetWeakPtr(), false);
 
-  real_time_domain_ =
-      make_scoped_refptr(new RealTimeDomain(delegate.get(), do_work_closure_));
+  // TODO(alexclarke): Change this to be a parameter that's passed in.
+  real_time_domain_ = make_scoped_refptr(new RealTimeDomain());
   RegisterTimeDomain(real_time_domain_);
 }
 
 TaskQueueManager::~TaskQueueManager() {
   TRACE_EVENT_OBJECT_DELETED_WITH_ID(disabled_by_default_tracing_category_,
                                      "TaskQueueManager", this);
 
   while (!queues_.empty())
     (*queues_.begin())->UnregisterTaskQueue();
 
   selector_.SetTaskQueueSelectorObserver(nullptr);
 }
 
 void TaskQueueManager::RegisterTimeDomain(
     const scoped_refptr<TimeDomain>& time_domain) {
   time_domains_.insert(time_domain);
+  time_domain->OnRegisterWithTaskQueueManager(delegate_.get(),
+                                              do_work_closure_);
 }
 
 void TaskQueueManager::UnregisterTimeDomain(
     const scoped_refptr<TimeDomain>& time_domain) {
   time_domains_.erase(time_domain);
 }
 
 scoped_refptr<internal::TaskQueueImpl> TaskQueueManager::NewTaskQueue(
     const TaskQueue::Spec& spec) {
   TRACE_EVENT1(tracing_category_,
@@ skipping 242 matching lines @@
 }
 
 void TaskQueueManager::OnTaskQueueEnabled(internal::TaskQueueImpl* queue) {
   DCHECK(main_thread_checker_.CalledOnValidThread());
   // Only schedule DoWork if there's something to do.
   if (!queue->work_queue().empty())
     MaybePostDoWorkOnMainRunner();
 }
 
 }  // namespace scheduler