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

base/message_loop/incoming_task_queue.cc

 // Copyright 2013 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 "base/message_loop/incoming_task_queue.h"
 
 #include <limits>
 
 #include "base/location.h"
 #include "base/message_loop/message_loop.h"
@@ skipping 79 matching lines @@
   DCHECK(work_queue->empty());
 
   // Acquire all we can from the inter-thread queue with one lock acquisition.
   AutoLock lock(incoming_queue_lock_);
   if (incoming_queue_.empty()) {
     // If the loop attempts to reload but there are no tasks in the incoming
     // queue, that means it will go to sleep waiting for more work. If the
     // incoming queue becomes nonempty we need to schedule it again.
     message_loop_scheduled_ = false;
   } else {
-    incoming_queue_.Swap(work_queue);
+    incoming_queue_.swap(*work_queue);
   }
   // Reset the count of high resolution tasks since our queue is now empty.
   int high_res_tasks = high_res_task_count_;
   high_res_task_count_ = 0;
   return high_res_tasks;
 }
 
 void IncomingTaskQueue::WillDestroyCurrentMessageLoop() {
   AutoLock lock(incoming_queue_lock_);
   message_loop_ = NULL;
@@ skipping 37 matching lines @@
 
   // Initialize the sequence number. The sequence number is used for delayed
   // tasks (to facilitate FIFO sorting when two tasks have the same
   // delayed_run_time value) and for identifying the task in about:tracing.
   pending_task->sequence_num = next_sequence_num_++;
 
   message_loop_->task_annotator()->DidQueueTask("MessageLoop::PostTask",
                                                 *pending_task);
 
   bool was_empty = incoming_queue_.empty();
-  incoming_queue_.push(*pending_task);
-  pending_task->task.Reset();
+  incoming_queue_.push(std::move(*pending_task));
 
   if (is_ready_for_scheduling_ &&
       (always_schedule_work_ || (!message_loop_scheduled_ && was_empty))) {
     ScheduleWork();
   }
 
   return true;
 }
 
 void IncomingTaskQueue::ScheduleWork() {
   DCHECK(is_ready_for_scheduling_);
   // Wake up the message loop.
   message_loop_->ScheduleWork();
   // After we've scheduled the message loop, we do not need to do so again
   // until we know it has processed all of the work in our queue and is
   // waiting for more work again. The message loop will always attempt to
   // reload from the incoming queue before waiting again so we clear this flag
   // in ReloadWorkQueue().
   message_loop_scheduled_ = true;
 }
 
 }  // namespace internal
 }  // namespace base