Revert of Move throttling of background timers into the renderer scheduler

components/scheduler/base/task_queue_manager.cc

Index: components/scheduler/base/task_queue_manager.cc
diff --git a/components/scheduler/base/task_queue_manager.cc b/components/scheduler/base/task_queue_manager.cc
index ec478db612e58792dba99b166fee5cbf8a633efb..b9df8756bf6a916d067286a2edb7b3866b753b9e 100644
--- a/components/scheduler/base/task_queue_manager.cc
+++ b/components/scheduler/base/task_queue_manager.cc
@@ -21,8 +21,7 @@
     const char* tracing_category,
     const char* disabled_by_default_tracing_category,
     const char* disabled_by_default_verbose_tracing_category)
-    : real_time_domain_(new RealTimeDomain()),
-      delegate_(delegate),
+    : delegate_(delegate),
       task_was_run_on_quiescence_monitored_queue_(false),
       pending_dowork_count_(0),
       work_batch_size_(1),
@@ -45,7 +44,8 @@
       base::Bind(&TaskQueueManager::DoWork, weak_factory_.GetWeakPtr(), false);
 
   // TODO(alexclarke): Change this to be a parameter that's passed in.
-  RegisterTimeDomain(real_time_domain_.get());
+  real_time_domain_ = make_scoped_refptr(new RealTimeDomain());
+  RegisterTimeDomain(real_time_domain_);
 }
 
 TaskQueueManager::~TaskQueueManager() {
@@ -58,13 +58,15 @@
   selector_.SetTaskQueueSelectorObserver(nullptr);
 }
 
-void TaskQueueManager::RegisterTimeDomain(TimeDomain* time_domain) {
+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(TimeDomain* time_domain) {
+void TaskQueueManager::UnregisterTimeDomain(
+    const scoped_refptr<TimeDomain>& time_domain) {
   time_domains_.erase(time_domain);
 }
 
@@ -75,7 +77,8 @@
   DCHECK(main_thread_checker_.CalledOnValidThread());
   TimeDomain* time_domain =
       spec.time_domain ? spec.time_domain : real_time_domain_.get();
-  DCHECK(time_domains_.find(time_domain) != time_domains_.end());
+  DCHECK(time_domains_.find(make_scoped_refptr(time_domain)) !=
+         time_domains_.end());
   scoped_refptr<internal::TaskQueueImpl> queue(
       make_scoped_refptr(new internal::TaskQueueImpl(
           this, time_domain, spec, disabled_by_default_tracing_category_,
@@ -112,7 +115,7 @@
   TRACE_EVENT0(disabled_by_default_tracing_category_,
                "TaskQueueManager::UpdateWorkQueues");
 
-  for (TimeDomain* time_domain : time_domains_) {
+  for (const scoped_refptr<TimeDomain>& time_domain : time_domains_) {
     time_domain->UpdateWorkQueues(should_trigger_wakeup, previous_task);
   }
 }
@@ -186,7 +189,7 @@
 
 bool TaskQueueManager::TryAdvanceTimeDomains() {
   bool can_advance = false;
-  for (TimeDomain* time_domain : time_domains_) {
+  for (const scoped_refptr<TimeDomain>& time_domain : time_domains_) {
     can_advance |= time_domain->MaybeAdvanceTime();
   }
   return can_advance;