Use a direct include of the message_loop header in ui/, part 1.

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/basictypes.h"
 #include "base/compiler_specific.h"
-#include "base/basictypes.h"
-#include "base/message_loop.h"
+#include "base/message_loop/message_loop.h"
 #include "testing/gtest/include/gtest/gtest.h"
 #include "ui/aura/test/aura_test_helper.h"
 
 namespace aura {
 class RootWindow;
 class Window;
 class WindowDelegate;
 namespace test {
 
 // A base class for aura unit tests.
@@ skipping 28 matching lines @@
   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_