Revert of Add ScopedTaskEnvironment::ExecutionControlMode.

base/task_scheduler/task_tracker.h

 // 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.
 
 #ifndef BASE_TASK_SCHEDULER_TASK_TRACKER_H_
 #define BASE_TASK_SCHEDULER_TASK_TRACKER_H_
 
 #include <memory>
 
 #include "base/atomicops.h"
@@ skipping 72 matching lines @@
   virtual void PerformRunTask(std::unique_ptr<Task> task,
                               const SequenceToken& sequence_token);
 
 #if DCHECK_IS_ON()
   // Returns true if this context should be exempt from blocking shutdown
   // DCHECKs.
   // TODO(robliao): Remove when http://crbug.com/698140 is fixed.
   virtual bool IsPostingBlockShutdownTaskAfterShutdownAllowed();
 #endif
 
-  // Returns the number of undelayed tasks that haven't completed their
-  // execution.
-  int GetNumPendingUndelayedTasksForTesting() const;
-
  private:
   class State;
 
   void PerformShutdown();
 
   // Called before WillPostTask() informs the tracing system that a task has
   // been posted. Updates |num_tasks_blocking_shutdown_| if necessary and
   // returns true if the current shutdown state allows the task to be posted.
   bool BeforePostTask(TaskShutdownBehavior shutdown_behavior);
 
@@ skipping 55 matching lines @@
   // Number of BLOCK_SHUTDOWN tasks posted during shutdown.
   HistogramBase::Sample num_block_shutdown_tasks_posted_during_shutdown_ = 0;
 
   DISALLOW_COPY_AND_ASSIGN(TaskTracker);
 };
 
 }  // namespace internal
 }  // namespace base
 
 #endif  // BASE_TASK_SCHEDULER_TASK_TRACKER_H_