Use base::MessageLoop in more files.

ui/base/win/singleton_hwnd.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.
 
 #include "ui/base/win/singleton_hwnd.h"
 
 #include "base/memory/singleton.h"
 #include "base/message_loop.h"
 
 namespace ui {
 
 // static
 SingletonHwnd* SingletonHwnd::GetInstance() {
   return Singleton<SingletonHwnd>::get();
 }
 
 void SingletonHwnd::AddObserver(Observer* observer) {
 
   if (!hwnd()) {
-    if (!MessageLoop::current() ||
-        MessageLoop::current()->type() != MessageLoop::TYPE_UI) {
+    if (!base::MessageLoop::current() ||
+        base::MessageLoop::current()->type() != base::MessageLoop::TYPE_UI) {
       // Creating this window in (e.g.) a renderer inhibits shutdown on
       // Windows. See http://crbug.com/230122 and http://crbug.com/236039.
       DLOG(ERROR) << "Cannot create windows on non-UI thread!";
       return;
     }
     WindowImpl::Init(NULL, gfx::Rect());
   }
   observer_list_.AddObserver(observer);
 }
 
@@ skipping 15 matching lines @@
   return false;
 }
 
 SingletonHwnd::SingletonHwnd() {
 }
 
 SingletonHwnd::~SingletonHwnd() {
 }
 
 }  // namespace ui