Revert of [cherrypick] Fix computation of runtime for throttled tasks

components/scheduler/renderer/throttling_helper.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 "components/scheduler/renderer/throttling_helper.h"
 
 #include "base/logging.h"
 #include "components/scheduler/base/real_time_domain.h"
+#include "components/scheduler/base/virtual_time_domain.h"
 #include "components/scheduler/child/scheduler_tqm_delegate.h"
 #include "components/scheduler/renderer/renderer_scheduler_impl.h"
-#include "components/scheduler/renderer/throttled_time_domain.h"
 #include "components/scheduler/renderer/web_frame_scheduler_impl.h"
 #include "third_party/WebKit/public/platform/WebFrameScheduler.h"
 
 namespace scheduler {
 
 ThrottlingHelper::ThrottlingHelper(RendererSchedulerImpl* renderer_scheduler,
                                    const char* tracing_category)
     : task_runner_(renderer_scheduler->ControlTaskRunner()),
       renderer_scheduler_(renderer_scheduler),
       tick_clock_(renderer_scheduler->tick_clock()),
       tracing_category_(tracing_category),
-      time_domain_(new ThrottledTimeDomain(this, tick_clock_)),
+      time_domain_(new VirtualTimeDomain(this, tick_clock_->NowTicks())),
       weak_factory_(this) {
   suspend_timers_when_backgrounded_closure_.Reset(base::Bind(
       &ThrottlingHelper::PumpThrottledTasks, weak_factory_.GetWeakPtr()));
   forward_immediate_work_closure_ =
       base::Bind(&ThrottlingHelper::OnTimeDomainHasImmediateWork,
                  weak_factory_.GetWeakPtr());
 
   renderer_scheduler_->RegisterTimeDomain(time_domain_.get());
 }
 
@@ skipping 95 matching lines @@
 
   pending_pump_throttled_tasks_runtime_ = throttled_runtime;
 
   suspend_timers_when_backgrounded_closure_.Cancel();
   task_runner_->PostDelayedTask(
       from_here, suspend_timers_when_backgrounded_closure_.callback(),
       pending_pump_throttled_tasks_runtime_ - now);
 }
 
 }  // namespace scheduler