Use std::unique_ptr<> for WebTaskRunner::clone

components/scheduler/child/web_task_runner_impl.cc

 // 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.
 
 #include "components/scheduler/child/web_task_runner_impl.h"
 
 #include "base/bind.h"
 #include "base/location.h"
 #include "base/memory/ptr_util.h"
 #include "components/scheduler/base/task_queue.h"
@@ skipping 42 matching lines @@
 
 base::TimeTicks WebTaskRunnerImpl::Now() const {
   TimeDomain* time_domain = task_queue_->GetTimeDomain();
   // It's possible task_queue_ has been Unregistered which can lead to a null
   // TimeDomain.  If that happens just return the current real time.
   if (!time_domain)
     return base::TimeTicks::Now();
   return time_domain->Now();
 }
 
-blink::WebTaskRunner* WebTaskRunnerImpl::clone() {
-  return new WebTaskRunnerImpl(task_queue_);
+std::unique_ptr<blink::WebTaskRunner> WebTaskRunnerImpl::clone() {
+  return base::WrapUnique(new WebTaskRunnerImpl(task_queue_));
 }
 
 void WebTaskRunnerImpl::runTask(
     std::unique_ptr<blink::WebTaskRunner::Task> task) {
   task->run();
 }
 
 }  // namespace scheduler