Revert of Move throttling of background timers into the renderer scheduler

components/scheduler/base/task_queue.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/base/task_queue.h"
 
 namespace scheduler {
 
-bool TaskQueue::HasPendingImmediateTask() const {
-  QueueState state = GetQueueState();
-  return state == QueueState::NEEDS_PUMPING || state == QueueState::HAS_WORK;
+bool TaskQueue::IsQueueEmpty() const {
+  return GetQueueState() == QueueState::EMPTY;
 }
 
 }  // namespace scheduler