Move MessageLoop to base namespace.

ui/views/test/webview_test_helper.h

 // 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.
 
 #ifndef UI_VIEWS_TEST_WEB_VIEW_TEST_HELPER_H_
 #define UI_VIEWS_TEST_WEB_VIEW_TEST_HELPER_H_
 
 #include "base/memory/scoped_ptr.h"
 
+namespace base {
 class MessageLoopForUI;
+}
 
 namespace content {
 class TestContentClientInitializer;
 class TestBrowserThread;
 }  // namespace content
 
 namespace views {
 
 class WebViewTestHelper {
  public:
-  explicit WebViewTestHelper(MessageLoopForUI* ui_loop);
+  explicit WebViewTestHelper(base::MessageLoopForUI* ui_loop);
   virtual ~WebViewTestHelper();
 
  private:
   scoped_ptr<content::TestContentClientInitializer>
       test_content_client_initializer_;
 
   scoped_ptr<content::TestBrowserThread> ui_thread_;
 
   DISALLOW_COPY_AND_ASSIGN(WebViewTestHelper);
 };
 
 }  // namespace views
 
 #endif  // UI_VIEWS_TEST_WEB_VIEW_TEST_HELPER_H_