Move MessageLoop to base namespace.

ui/aura/test/aura_test_base.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_AURA_TEST_AURA_TEST_BASE_H_
 #define UI_AURA_TEST_AURA_TEST_BASE_H_
 
 #include "base/compiler_specific.h"
 #include "base/basictypes.h"
 #include "base/message_loop.h"
@@ skipping 26 matching lines @@
 
   // Attach |window| to the current shell's root window.
   void SetDefaultParentByPrimaryRootWindow(aura::Window* window);
 
  protected:
   void RunAllPendingInMessageLoop();
 
   RootWindow* root_window() { return helper_->root_window(); }
 
  private:
-  MessageLoopForUI message_loop_;
+  base::MessageLoopForUI message_loop_;
   scoped_ptr<AuraTestHelper> helper_;
 
   DISALLOW_COPY_AND_ASSIGN(AuraTestBase);
 };
 
 }  // namespace test
 }  // namespace aura
 
 #endif  // UI_AURA_TEST_AURA_TEST_BASE_H_