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

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 <utility>
 
 #include "base/location.h"
 #include "base/message_loop/message_loop.h"
 #include "base/synchronization/waitable_event.h"
 #include "base/time/time.h"
 #include "build/build_config.h"
 
 namespace base {
 namespace internal {
 
@@ skipping 34 matching lines @@
     : high_res_task_count_(0),
       message_loop_(message_loop),
       next_sequence_num_(0),
       message_loop_scheduled_(false),
       always_schedule_work_(AlwaysNotifyPump(message_loop_->type())),
       is_ready_for_scheduling_(false) {
 }
 
 bool IncomingTaskQueue::AddToIncomingQueue(
     const tracked_objects::Location& from_here,
-    const Closure& task,
+    Closure task,
     TimeDelta delay,
     bool nestable) {
   DLOG_IF(WARNING,
           delay.InSeconds() > kTaskDelayWarningThresholdInSeconds)
       << "Requesting super-long task delay period of " << delay.InSeconds()
       << " seconds from here: " << from_here.ToString();
 
-  PendingTask pending_task(from_here, task, CalculateDelayedRuntime(delay),
-                           nestable);
+  PendingTask pending_task(from_here, std::move(task),
+                           CalculateDelayedRuntime(delay), nestable);
 #if defined(OS_WIN)
   // We consider the task needs a high resolution timer if the delay is
   // more than 0 and less than 32ms. This caps the relative error to
   // less than 50% : a 33ms wait can wake at 48ms since the default
   // resolution on Windows is between 10 and 15ms.
   if (delay > TimeDelta() &&
       delay.InMilliseconds() < (2 * Time::kMinLowResolutionThresholdMs)) {
     pending_task.is_high_res = true;
   }
 #endif
@@ skipping 108 matching lines @@
   // that wants to post a task will be blocked until this thread switches back
   // in and releases |incoming_queue_lock_|.
   if (schedule_work)
     message_loop_->ScheduleWork();
 
   return true;
 }
 
 }  // namespace internal
 }  // namespace base