Revert of [scheduler] Add TaskQueue::Observer

third_party/WebKit/Source/platform/scheduler/base/real_time_domain.cc

 // Copyright 2015 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 "platform/scheduler/base/real_time_domain.h"
 
 #include "base/bind.h"
 #include "platform/scheduler/base/task_queue_impl.h"
 #include "platform/scheduler/base/task_queue_manager.h"
 #include "platform/scheduler/base/task_queue_manager_delegate.h"
 
 namespace blink {
 namespace scheduler {
 
 RealTimeDomain::RealTimeDomain(const char* tracing_category)
-    : tracing_category_(tracing_category), task_queue_manager_(nullptr) {}
+    : TimeDomain(nullptr),
+      tracing_category_(tracing_category),
+      task_queue_manager_(nullptr) {}
+
+RealTimeDomain::RealTimeDomain(TimeDomain::Observer* observer,
+                               const char* tracing_category)
+    : TimeDomain(observer),
+      tracing_category_(tracing_category),
+      task_queue_manager_(nullptr) {}
 
 RealTimeDomain::~RealTimeDomain() {}
 
 void RealTimeDomain::OnRegisterWithTaskQueueManager(
     TaskQueueManager* task_queue_manager) {
   task_queue_manager_ = task_queue_manager;
   DCHECK(task_queue_manager_);
 }
 
 LazyNow RealTimeDomain::CreateLazyNow() const {
   return task_queue_manager_->CreateLazyNow();
 }
 
 base::TimeTicks RealTimeDomain::Now() const {
   return task_queue_manager_->Delegate()->NowTicks();
 }
 
-void RealTimeDomain::RequestWakeUpAt(base::TimeTicks now,
+void RealTimeDomain::RequestWakeupAt(base::TimeTicks now,
                                      base::TimeTicks run_time) {
   // NOTE this is only called if the scheduled runtime is sooner than any
   // previously scheduled runtime, or there is no (outstanding) previously
   // scheduled runtime.
   task_queue_manager_->MaybeScheduleDelayedWork(FROM_HERE, this, now, run_time);
 }
 
-void RealTimeDomain::CancelWakeUpAt(base::TimeTicks run_time) {
+void RealTimeDomain::CancelWakeupAt(base::TimeTicks run_time) {
   task_queue_manager_->CancelDelayedWork(this, run_time);
 }
 
 base::Optional<base::TimeDelta> RealTimeDomain::DelayTillNextTask(
     LazyNow* lazy_now) {
   base::TimeTicks next_run_time;
   if (!NextScheduledRunTime(&next_run_time))
     return base::nullopt;
 
   base::TimeTicks now = lazy_now->Now();
@@ skipping 10 matching lines @@
 }
 
 void RealTimeDomain::AsValueIntoInternal(
     base::trace_event::TracedValue* state) const {}
 
 const char* RealTimeDomain::GetName() const {
   return "RealTimeDomain";
 }
 }  // namespace scheduler
 }  // namespace blink