Revert of [Reland] Scheduler refactoring to virtually eliminate redundant DoWorks

cc/test/ordered_simple_task_runner.h

 // 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.
 
 #ifndef CC_TEST_ORDERED_SIMPLE_TASK_RUNNER_H_
 #define CC_TEST_ORDERED_SIMPLE_TASK_RUNNER_H_
 
 #include <stddef.h>
 
 #include <limits>
@@ skipping 112 matching lines @@
 
   // Keep running until a task which didn't exist initially would run.
   base::Callback<bool(void)> TaskExistedInitially();
 
   // Stop running tasks when NextTaskTime() >= stop_at
   base::Callback<bool(void)> NowBefore(base::TimeTicks stop_at);
 
   // Advance Now() to the next task to run.
   base::Callback<bool(void)> AdvanceNow();
 
-  // Removes all tasks whose weak pointer has been revoked.
-  void RemoveCancelledTasks();
-
  protected:
   static bool TaskRunCountBelowCallback(size_t max_tasks, size_t* task_run);
   bool TaskExistedInitiallyCallback(
       const std::set<TestOrderablePendingTask>& existing_tasks);
   bool NowBeforeCallback(base::TimeTicks stop_at);
   bool AdvanceNowCallback();
 
   ~OrderedSimpleTaskRunner() override;
 
   base::ThreadChecker thread_checker_;
 
   bool advance_now_;
   // Not owned.
   base::SimpleTestTickClock* now_src_;
 
   size_t max_tasks_;
 
   bool inside_run_tasks_until_;
   std::set<TestOrderablePendingTask> pending_tasks_;
 
  private:
   DISALLOW_COPY_AND_ASSIGN(OrderedSimpleTaskRunner);
 };
 
 }  // namespace cc
 
 #endif  // CC_TEST_ORDERED_SIMPLE_TASK_RUNNER_H_