Handle delayed tasks more natively in the scheduler

cc/test/ordered_simple_task_runner.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 "cc/test/ordered_simple_task_runner.h"
 
 #include <limits>
 #include <set>
 #include <sstream>
 #include <string>
@@ skipping 109 matching lines @@
   TRACE_TASK("OrderedSimpleTaskRunner::PostNonNestableDelayedTask", pt);
   pending_tasks_.insert(pt);
   return true;
 }
 
 bool OrderedSimpleTaskRunner::RunsTasksOnCurrentThread() const {
   DCHECK(thread_checker_.CalledOnValidThread());
   return true;
 }
 
+size_t OrderedSimpleTaskRunner::NumPendingTasks() const {
+  return pending_tasks_.size();
+}
+
 bool OrderedSimpleTaskRunner::HasPendingTasks() const {
   return pending_tasks_.size() > 0;
 }
 
 base::TimeTicks OrderedSimpleTaskRunner::NextTaskTime() {
   if (pending_tasks_.size() <= 0) {
     return TestNowSource::kAbsoluteMaxNow;
   }
 
   return pending_tasks_.begin()->GetTimeToRun();
@@ skipping 185 matching lines @@
 
 bool OrderedSimpleTaskRunner::AdvanceNowCallback() {
   base::TimeTicks next_task_time = NextTaskTime();
   if (now_src_->Now() < next_task_time) {
     now_src_->SetNow(next_task_time);
   }
   return true;
 }
 
 }  // namespace cc