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

components/history/core/browser/history_service.cc

 // Copyright (c) 2012 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.
 
 // The history system runs on a background thread so that potentially slow
 // database operations don't delay the browser. This backend processing is
 // represented by HistoryBackend. The HistoryService's job is to dispatch to
 // that thread.
 //
 // Main thread                       History thread
@@ skipping 897 matching lines @@
 }
 
 void HistoryService::ScheduleAutocomplete(
     const base::Callback<void(HistoryBackend*, URLDatabase*)>& callback) {
   DCHECK(thread_checker_.CalledOnValidThread());
   ScheduleTask(PRIORITY_UI, base::Bind(&HistoryBackend::ScheduleAutocomplete,
                                        history_backend_, callback));
 }
 
 void HistoryService::ScheduleTask(SchedulePriority priority,
-                                  const base::Closure& task) {
+                                  base::Closure task) {
   DCHECK(thread_checker_.CalledOnValidThread());
   CHECK(backend_task_runner_);
   // TODO(brettw): Do prioritization.
-  backend_task_runner_->PostTask(FROM_HERE, task);
+  backend_task_runner_->PostTask(FROM_HERE, std::move(task));
 }
 
 base::WeakPtr<HistoryService> HistoryService::AsWeakPtr() {
   DCHECK(thread_checker_.CalledOnValidThread());
   return weak_ptr_factory_.GetWeakPtr();
 }
 
 syncer::SyncMergeResult HistoryService::MergeDataAndStartSyncing(
     syncer::ModelType type,
     const syncer::SyncDataList& initial_sync_data,
@@ skipping 212 matching lines @@
   return favicon_changed_callback_list_.Add(callback);
 }
 
 void HistoryService::NotifyFaviconsChanged(const std::set<GURL>& page_urls,
                                            const GURL& icon_url) {
   DCHECK(thread_checker_.CalledOnValidThread());
   favicon_changed_callback_list_.Notify(page_urls, icon_url);
 }
 
 }  // namespace history