Pass Callback to TaskRunner by value and consume it on invocation (1)

base/test/test_simple_task_runner.h

 // 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.
 
 #ifndef BASE_TEST_TEST_SIMPLE_TASK_RUNNER_H_
 #define BASE_TEST_TEST_SIMPLE_TASK_RUNNER_H_
 
 #include <deque>
 
+#include "base/callback.h"
 #include "base/compiler_specific.h"
 #include "base/macros.h"
 #include "base/single_thread_task_runner.h"
 #include "base/synchronization/lock.h"
 #include "base/test/test_pending_task.h"
 #include "base/threading/platform_thread.h"
 
 namespace base {
 
 class TimeDelta;
@@ skipping 16 matching lines @@
 // (e.g., to post more tasks).
 //
 // Note that, like any TaskRunner, TestSimpleTaskRunner is
 // ref-counted.
 class TestSimpleTaskRunner : public SingleThreadTaskRunner {
  public:
   TestSimpleTaskRunner();
 
   // SingleThreadTaskRunner implementation.
   bool PostDelayedTask(const tracked_objects::Location& from_here,
-                       const Closure& task,
+                       Closure task,
                        TimeDelta delay) override;
   bool PostNonNestableDelayedTask(const tracked_objects::Location& from_here,
-                                  const Closure& task,
+                                  Closure task,
                                   TimeDelta delay) override;
 
   bool RunsTasksOnCurrentThread() const override;
 
   std::deque<TestPendingTask> TakePendingTasks();
   size_t NumPendingTasks() const;
   bool HasPendingTask() const;
   base::TimeDelta NextPendingTaskDelay() const;
   base::TimeDelta FinalPendingTaskDelay() const;
 
@@ skipping 20 matching lines @@
   mutable Lock lock_;
 
   std::deque<TestPendingTask> pending_tasks_;
 
   DISALLOW_COPY_AND_ASSIGN(TestSimpleTaskRunner);
 };
 
 }  // namespace base
 
 #endif  // BASE_TEST_TEST_SIMPLE_TASK_RUNNER_H_