Revert "content: Remove use of MessageLoopProxy and deprecated MessageLoop APIs"

content/browser/fileapi/mock_file_change_observer.cc

 // 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 "content/browser/fileapi/mock_file_change_observer.h"
 
-#include "base/thread_task_runner_handle.h"
-
 namespace storage {
 
 MockFileChangeObserver::MockFileChangeObserver()
     : create_file_count_(0),
       create_file_from_count_(0),
       remove_file_count_(0),
       modify_file_count_(0),
       create_directory_count_(0),
       remove_directory_count_(0) {}
 
 MockFileChangeObserver::~MockFileChangeObserver() {}
 
 // static
 ChangeObserverList MockFileChangeObserver::CreateList(
     MockFileChangeObserver* observer) {
   ChangeObserverList list;
-  return list.AddObserver(observer, base::ThreadTaskRunnerHandle::Get().get());
+  return list.AddObserver(observer, base::MessageLoopProxy::current().get());
 }
 
 void MockFileChangeObserver::OnCreateFile(const FileSystemURL& url) {
   create_file_count_++;
 }
 
 void MockFileChangeObserver::OnCreateFileFrom(const FileSystemURL& url,
                                               const FileSystemURL& src) {
   create_file_from_count_++;
 }
 
 void MockFileChangeObserver::OnRemoveFile(const FileSystemURL& url) {
   remove_file_count_++;
 }
 
 void MockFileChangeObserver::OnModifyFile(const FileSystemURL& url) {
   modify_file_count_++;
 }
 
 void MockFileChangeObserver::OnCreateDirectory(const FileSystemURL& url) {
   create_directory_count_++;
 }
 
 void MockFileChangeObserver::OnRemoveDirectory(const FileSystemURL& url) {
   remove_directory_count_++;
 }
 
 }  // namespace storage