Replace base::Callback with base::OnceCallback in base::PendingTask

base/pending_task.h

 // Copyright (c) 2011 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_PENDING_TASK_H_
 #define BASE_PENDING_TASK_H_
 
 #include <queue>
 
 #include "base/base_export.h"
 #include "base/callback.h"
 #include "base/location.h"
 #include "base/time/time.h"
 #include "base/tracking_info.h"
 
 namespace base {
 
+using internal::OnceClosure;

[fdoray, 2016/10/06 17:37:22]

Avoid using "using" in a header file.

[tzik, 2016/10/13 05:58:04]

Removed. This is no longer needed after I moved it out from the internal
namespace.

+
 // Contains data about a pending task. Stored in TaskQueue and DelayedTaskQueue
 // for use by classes that queue and execute tasks.
 struct BASE_EXPORT PendingTask : public TrackingInfo {
+  PendingTask(const tracked_objects::Location& posted_from, OnceClosure task);
   PendingTask(const tracked_objects::Location& posted_from,
-              Closure task);
-  PendingTask(const tracked_objects::Location& posted_from,
-              Closure task,
+              OnceClosure task,
               TimeTicks delayed_run_time,
               bool nestable);
   PendingTask(PendingTask&& other);
   ~PendingTask();
 
   PendingTask& operator=(PendingTask&& other);
 
   // Used to support sorting.
   bool operator<(const PendingTask& other) const;
 
   // The task to run.
-  Closure task;
+  OnceClosure task;
 
   // The site this PendingTask was posted from.
   tracked_objects::Location posted_from;
 
   // Secondary sort key for run time.
   int sequence_num;
 
   // OK to dispatch from a nested loop.
   bool nestable;
 
   // Needs high resolution timers.
   bool is_high_res;
 };
 
 using TaskQueue = std::queue<PendingTask>;
 
 // PendingTasks are sorted by their |delayed_run_time| property.
 using DelayedTaskQueue = std::priority_queue<base::PendingTask>;
 
 }  // namespace base
 
 #endif  // BASE_PENDING_TASK_H_