Add base::PostDelayedTask(WithTraits).

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>
 
 #include "base/base_export.h"
 #include "base/callback_forward.h"
 #include "base/memory/ref_counted.h"
 #include "base/sequenced_task_runner.h"
 #include "base/single_thread_task_runner.h"
 #include "base/task_runner.h"
 #include "base/task_scheduler/task_traits.h"
+#include "base/time/time.h"
 
 namespace tracked_objects {
 class Location;
 }
 
 namespace base {
 
 class HistogramBase;
 class SchedulerWorkerPoolParams;
 
 // Interface for a task scheduler and static methods to manage the instance used
 // by the post_task.h API. Note: all base/task_scheduler users should go through
 // post_task.h instead of TaskScheduler except for the one callsite per process
 // which manages the process' instance.
 class BASE_EXPORT TaskScheduler {
  public:
   // Returns the index of the worker pool in which a task with |traits| should
   // run. This should be coded in a future-proof way: new traits should
   // gracefully map to a default pool.
   using WorkerPoolIndexForTraitsCallback =
       Callback<size_t(const TaskTraits& traits)>;
 
   virtual ~TaskScheduler() = default;
 
-  // Posts |task| with specific |traits|.
+  // Posts |task| with a |delay| and specific |traits|. |delay| can be zero.
   // 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;
+  virtual void PostDelayedTaskWithTraits(
+      const tracked_objects::Location& from_here,
+      const TaskTraits& traits,
+      const Closure& task,
+      TimeDelta delay) = 0;
 
   // Returns a TaskRunner whose PostTask invocations result in scheduling tasks
   // using |traits|. Tasks may run in any order and in parallel.
   virtual scoped_refptr<TaskRunner> CreateTaskRunnerWithTraits(
       const TaskTraits& traits) = 0;
 
   // Returns a SequencedTaskRunner whose PostTask invocations result in
   // scheduling tasks using |traits|. Tasks run one at a time in posting order.
   virtual scoped_refptr<SequencedTaskRunner>
   CreateSequencedTaskRunnerWithTraits(const TaskTraits& traits) = 0;
@@ skipping 53 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_