Convert Pass()→std::move() for iOS build.

ios/web/app/web_main_loop.mm

 // 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 "ios/web/app/web_main_loop.h"
 
 #include <stddef.h>
 
+#include <utility>
+
 #include "base/bind.h"
 #include "base/command_line.h"
 #include "base/logging.h"
 #include "base/message_loop/message_loop.h"
 #include "base/metrics/histogram.h"
 #include "base/path_service.h"
 #include "base/power_monitor/power_monitor.h"
 #include "base/power_monitor/power_monitor_device_source.h"
 #include "base/process/process_metrics.h"
 #include "base/system_monitor/system_monitor.h"
@@ skipping 53 matching lines @@
 
   InitializeMainThread();
 
 #if 0
   // TODO(crbug.com/228014): SystemMonitor is not working properly on iOS.
   system_monitor_.reset(new base::SystemMonitor);
 #endif
   // TODO(rohitrao): Do we need PowerMonitor on iOS, or can we get rid of it?
   scoped_ptr<base::PowerMonitorSource> power_monitor_source(
       new base::PowerMonitorDeviceSource());
-  power_monitor_.reset(new base::PowerMonitor(power_monitor_source.Pass()));
+  power_monitor_.reset(new base::PowerMonitor(std::move(power_monitor_source)));
   network_change_notifier_.reset(net::NetworkChangeNotifier::Create());
 
   if (parts_) {
     parts_->PostMainMessageLoopStart();
   }
 }
 
 void WebMainLoop::CreateStartupTasks() {
   int result = 0;
   result = PreCreateThreads();
@@ skipping 173 matching lines @@
   main_thread_.reset(
       new WebThreadImpl(WebThread::UI, base::MessageLoop::current()));
 }
 
 int WebMainLoop::WebThreadsStarted() {
   cookie_notification_bridge_.reset(new CookieNotificationBridge);
   return result_code_;
 }
 
 }  // namespace web