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

third_party/WebKit/Source/platform/scheduler/child/web_task_runner_impl.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_CHILD_WEB_TASK_RUNNER_IMPL_H_
 #define THIRD_PARTY_WEBKIT_SOURCE_PLATFORM_SCHEDULER_CHILD_WEB_TASK_RUNNER_IMPL_H_
 
 #include <memory>
 
+#include "base/callback.h"
 #include "base/macros.h"
 #include "base/memory/ref_counted.h"
 #include "base/time/time.h"
 #include "platform/WebTaskRunner.h"
 #include "public/platform/WebCommon.h"
 
 namespace blink {
 namespace scheduler {
 class TaskQueue;
 
 class BLINK_PLATFORM_EXPORT WebTaskRunnerImpl : public WebTaskRunner {
  public:
   static RefPtr<WebTaskRunnerImpl> create(scoped_refptr<TaskQueue> task_queue);
 
   // WebTaskRunner implementation:
   void postDelayedTask(const WebTraceLocation&,
-                       const base::Closure&,
+                       base::Closure,
                        double delayMs) override;
   bool runsTasksOnCurrentThread() override;
   double virtualTimeSeconds() const override;
   double monotonicallyIncreasingVirtualTimeSeconds() const override;
   base::SingleThreadTaskRunner* toSingleThreadTaskRunner() override;
 
  private:
   explicit WebTaskRunnerImpl(scoped_refptr<TaskQueue> task_queue);
   ~WebTaskRunnerImpl() override;
 
   base::TimeTicks Now() const;
 
   scoped_refptr<TaskQueue> task_queue_;
 
   DISALLOW_COPY_AND_ASSIGN(WebTaskRunnerImpl);
 };
 
 }  // namespace scheduler
 }  // namespace blink
 
 #endif  // THIRD_PARTY_WEBKIT_SOURCE_PLATFORM_SCHEDULER_CHILD_WEB_TASK_RUNNER_IMPL_H_