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

third_party/WebKit/Source/platform/scheduler/test/lazy_scheduler_message_loop_delegate_for_tests.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_TEST_LAZY_SCHEDULER_MESSAGE_LOOP_DELEGATE_FOR_TESTS_H_
 #define THIRD_PARTY_WEBKIT_SOURCE_PLATFORM_SCHEDULER_TEST_LAZY_SCHEDULER_MESSAGE_LOOP_DELEGATE_FOR_TESTS_H_
 
 #include <memory>
 
+#include "base/callback.h"
 #include "base/macros.h"
 #include "base/message_loop/message_loop.h"
 #include "base/time/tick_clock.h"
 #include "platform/scheduler/child/scheduler_tqm_delegate.h"
 
 namespace blink {
 namespace scheduler {
 
 // This class connects the scheduler to a MessageLoop, but unlike
 // SchedulerMessageLoopDelegate it allows the message loop to be created lazily
 // after the scheduler has been brought up. This is needed in testing scenarios
 // where Blink is initialized before a MessageLoop has been created.
 //
 // TODO(skyostil): Fix the relevant test suites and remove this class
 // (crbug.com/495659).
 class LazySchedulerMessageLoopDelegateForTests : public SchedulerTqmDelegate {
  public:
   static scoped_refptr<LazySchedulerMessageLoopDelegateForTests> Create();
 
   // SchedulerTqmDelegate implementation
   void SetDefaultTaskRunner(
       scoped_refptr<base::SingleThreadTaskRunner> task_runner) override;
   void RestoreDefaultTaskRunner() override;
   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;
 
  private:
@@ skipping 13 matching lines @@
 
   base::MessageLoop::NestingObserver* pending_observer_;
 
   DISALLOW_COPY_AND_ASSIGN(LazySchedulerMessageLoopDelegateForTests);
 };
 
 }  // namespace scheduler
 }  // namespace blink
 
 #endif  // THIRD_PARTY_WEBKIT_SOURCE_PLATFORM_SCHEDULER_TEST_LAZY_SCHEDULER_MESSAGE_LOOP_DELEGATE_FOR_TESTS_H_