Remove calls to deprecated MessageLoop methods on Windows and Linux.

components/arc/standalone/arc_standalone_bridge_runner.cc

 // Copyright 2016 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/arc/standalone/arc_standalone_bridge_runner.h"
 
 #include "base/bind.h"
 #include "base/run_loop.h"
+#include "base/single_thread_task_runner.h"
 
 namespace arc {
 
 ArcStandaloneBridgeRunner::ArcStandaloneBridgeRunner() : exit_code_(0) {
 }
 
 ArcStandaloneBridgeRunner::~ArcStandaloneBridgeRunner() {
 }
 
 int ArcStandaloneBridgeRunner::Run() {
   DCHECK(thread_checker_.CalledOnValidThread());
   run_loop_.reset(new base::RunLoop());
   run_loop_->Run();
   run_loop_.reset(nullptr);
 
   return exit_code_;
 }
 
 void ArcStandaloneBridgeRunner::Stop(int exit_code) {
   DCHECK(thread_checker_.CalledOnValidThread());
   exit_code_ = exit_code;
   CHECK(run_loop_);
-  message_loop_.PostTask(FROM_HERE, run_loop_->QuitClosure());
+  message_loop_.task_runner()->PostTask(FROM_HERE, run_loop_->QuitClosure());
 }
 
 }  // namespace arc