Make PendingTask move-only and pass it by value on retaining params

components/scheduler/base/task_queue_manager.cc

 // Copyright 2014 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 "components/scheduler/base/task_queue_manager.h"
 
 #include <queue>
 #include <set>
 
 #include "base/bind.h"
@@ skipping 284 matching lines @@
 
   currently_executing_task_queue_ = prev_executing_task_queue;
 
   if (queue->GetShouldNotifyObservers()) {
     FOR_EACH_OBSERVER(base::MessageLoop::TaskObserver, task_observers_,
                       DidProcessTask(pending_task));
     queue->NotifyDidProcessTask(pending_task);
   }
 
   pending_task.task.Reset();
-  *out_previous_task = pending_task;
+  *out_previous_task = std::move(pending_task);
   return ProcessTaskResult::EXECUTED;
 }
 
 void TaskQueueManager::MaybeRecordTaskDelayHistograms(
     const internal::TaskQueueImpl::Task& pending_task,
     const internal::TaskQueueImpl* queue) {
   if ((task_count_++ % kRecordRecordTaskDelayHistogramsEveryNTasks) != 0)
     return;
 
   // Record delayed task lateness and immediate task queueing durations, but
@@ skipping 91 matching lines @@
     internal::WorkQueue* work_queue) {
   DCHECK(main_thread_checker_.CalledOnValidThread());
   DCHECK(!work_queue->Empty());
   if (observer_) {
     observer_->OnTriedToExecuteBlockedTask(*work_queue->task_queue(),
                                            *work_queue->GetFrontTask());
   }
 }
 
 }  // namespace scheduler