Replace Closure in TaskRunner::PostTask with OneShotCallback

base/task_scheduler/task_scheduler.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_SCHEDULER_H_
 #define BASE_TASK_SCHEDULER_TASK_SCHEDULER_H_
 
 #include <memory>
 #include <vector>
 
@@ skipping 22 matching lines @@
   // gracefully map to a default pool.
   using WorkerPoolIndexForTraitsCallback =
       Callback<size_t(const TaskTraits& traits)>;
 
   virtual ~TaskScheduler() = default;
 
   // Posts |task| with specific |traits|.
   // For one off tasks that don't require a TaskRunner.
   virtual void PostTaskWithTraits(const tracked_objects::Location& from_here,
                                   const TaskTraits& traits,
-                                  const Closure& task) = 0;
+                                  OnceClosure task) = 0;
 
   // Returns a TaskRunner whose PostTask invocations will result in scheduling
   // Tasks with |traits| which will be executed according to |execution_mode|.
   virtual scoped_refptr<TaskRunner> CreateTaskRunnerWithTraits(
       const TaskTraits& traits,
       ExecutionMode execution_mode) = 0;
 
   // Synchronously shuts down the scheduler. Once this is called, only tasks
   // posted with the BLOCK_SHUTDOWN behavior will be run. When this returns:
   // - All SKIP_ON_SHUTDOWN tasks that were already running have completed their
@@ skipping 28 matching lines @@
 
   // Retrieve the TaskScheduler set via CreateAndSetDefaultTaskScheduler() or
   // SetInstance(). This should be used very rarely; most users of TaskScheduler
   // should use the post_task.h API.
   static TaskScheduler* GetInstance();
 };
 
 }  // namespace base
 
 #endif  // BASE_TASK_SCHEDULER_TASK_SCHEDULER_H_