Pass Callback by value on PostTaskAndReply family

base/threading/worker_pool.cc

 // Copyright (c) 2012 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.
 
 #include "base/threading/worker_pool.h"
 
+#include <utility>
+
 #include "base/bind.h"
 #include "base/compiler_specific.h"
 #include "base/debug/leak_annotations.h"
 #include "base/macros.h"
 #include "base/task_runner.h"
 #include "base/threading/post_task_and_reply_impl.h"
 #include "base/tracked_objects.h"
 
 namespace base {
 
@@ skipping 76 matching lines @@
   TaskRunnerHolder() {
     taskrunners_[0] = new WorkerPoolTaskRunner(false);
     taskrunners_[1] = new WorkerPoolTaskRunner(true);
   }
   scoped_refptr<TaskRunner> taskrunners_[2];
 };
 
 }  // namespace
 
 bool WorkerPool::PostTaskAndReply(const tracked_objects::Location& from_here,
-                                  const Closure& task,
-                                  const Closure& reply,
+                                  Closure task,
+                                  Closure reply,
                                   bool task_is_slow) {
   // Do not report PostTaskAndReplyRelay leaks in tests. There's nothing we can
   // do about them because WorkerPool doesn't have a flushing API.
   // http://crbug.com/248513
   // http://crbug.com/290897
   // Note: this annotation does not cover tasks posted through a TaskRunner.
   ANNOTATE_SCOPED_MEMORY_LEAK;
-  return PostTaskAndReplyWorkerPool(task_is_slow).PostTaskAndReply(
-      from_here, task, reply);
+  return PostTaskAndReplyWorkerPool(task_is_slow)
+      .PostTaskAndReply(from_here, std::move(task), std::move(reply));
 }
 
 // static
 const scoped_refptr<TaskRunner>&
 WorkerPool::GetTaskRunner(bool tasks_are_slow) {
   static auto task_runner_holder = new TaskRunnerHolder();
   return task_runner_holder->taskrunners_[tasks_are_slow];
 }
 
 }  // namespace base