Revert of Add ScopedTaskEnvironment::ExecutionControlMode.

base/task_scheduler/task_tracker.cc

 // Copyright 2016 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 "base/task_scheduler/task_tracker.h"
 
 #include <limits>
 #include <string>
 
 #include "base/callback.h"
@@ skipping 370 matching lines @@
     }
   }
 }
 
 #if DCHECK_IS_ON()
 bool TaskTracker::IsPostingBlockShutdownTaskAfterShutdownAllowed() {
   return false;
 }
 #endif
 
-int TaskTracker::GetNumPendingUndelayedTasksForTesting() const {
-  return subtle::Acquire_Load(&num_pending_undelayed_tasks_);
-}
-
 bool TaskTracker::BeforePostTask(TaskShutdownBehavior shutdown_behavior) {
   if (shutdown_behavior == TaskShutdownBehavior::BLOCK_SHUTDOWN) {
     // BLOCK_SHUTDOWN tasks block shutdown between the moment they are posted
     // and the moment they complete their execution.
     const bool shutdown_started = state_->IncrementNumTasksBlockingShutdown();
 
     if (shutdown_started) {
       AutoSchedulerLock auto_lock(shutdown_lock_);
 
       // A BLOCK_SHUTDOWN task posted after shutdown has completed is an
@@ skipping 111 matching lines @@
   task_latency_histograms_[static_cast<int>(task->traits.priority())]
                           [task->traits.may_block() ||
                                    task->traits.with_base_sync_primitives()
                                ? 1
                                : 0]
                               ->Add(task_latency.InMicroseconds());
 }
 
 }  // namespace internal
 }  // namespace base