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

third_party/WebKit/Source/platform/scheduler/base/task_queue_manager_delegate_for_test.h

 // Copyright 2015 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 THIRD_PARTY_WEBKIT_SOURCE_PLATFORM_SCHEDULER_BASE_TASK_QUEUE_MANAGER_DELEGATE_FOR_TEST_H_
 #define THIRD_PARTY_WEBKIT_SOURCE_PLATFORM_SCHEDULER_BASE_TASK_QUEUE_MANAGER_DELEGATE_FOR_TEST_H_
 
 #include <memory>
 
+#include "base/callback.h"
 #include "base/macros.h"
 #include "base/time/tick_clock.h"
 #include "platform/scheduler/base/task_queue_manager_delegate.h"
 
 namespace blink {
 namespace scheduler {
 
 class TaskQueueManagerDelegateForTest : public TaskQueueManagerDelegate {
  public:
   static scoped_refptr<TaskQueueManagerDelegateForTest> Create(
       scoped_refptr<base::SingleThreadTaskRunner> task_runner,
       std::unique_ptr<base::TickClock> time_source);
 
   // NestableSingleThreadTaskRunner implementation
   bool PostDelayedTask(const tracked_objects::Location& from_here,
-                       const base::Closure& task,
+                       base::Closure task,
                        base::TimeDelta delay) override;
   bool PostNonNestableDelayedTask(const tracked_objects::Location& from_here,
-                                  const base::Closure& task,
+                                  base::Closure task,
                                   base::TimeDelta delay) override;
   bool RunsTasksOnCurrentThread() const override;
   bool IsNested() const override;
   void AddNestingObserver(
       base::MessageLoop::NestingObserver* observer) override;
   void RemoveNestingObserver(
       base::MessageLoop::NestingObserver* observer) override;
   base::TimeTicks NowTicks() override;
 
  protected:
   ~TaskQueueManagerDelegateForTest() override;
   TaskQueueManagerDelegateForTest(
       scoped_refptr<base::SingleThreadTaskRunner> task_runner,
       std::unique_ptr<base::TickClock> time_source);
 
  private:
   scoped_refptr<base::SingleThreadTaskRunner> task_runner_;
   std::unique_ptr<base::TickClock> time_source_;
 
   DISALLOW_COPY_AND_ASSIGN(TaskQueueManagerDelegateForTest);
 };
 
 }  // namespace scheduler
 }  // namespace blink
 
 #endif  // THIRD_PARTY_WEBKIT_SOURCE_PLATFORM_SCHEDULER_BASE_TASK_QUEUE_MANAGER_DELEGATE_FOR_TEST_H_