Use a direct include of the message_loop header in content/, part 3.

content/public/test/test_renderer_host.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 CONTENT_PUBLIC_TEST_TEST_RENDERER_HOST_H_
 #define CONTENT_PUBLIC_TEST_TEST_RENDERER_HOST_H_
 
 #include "base/memory/scoped_ptr.h"
-#include "base/message_loop.h"
+#include "base/message_loop/message_loop.h"
 #include "content/public/browser/render_view_host.h"
 #include "content/public/common/page_transition_types.h"
 #include "content/public/test/test_browser_thread_bundle.h"
 #include "testing/gtest/include/gtest/gtest.h"
 
 #if defined(USE_AURA)
 #include "ui/aura/test/aura_test_helper.h"
 #endif
 
 namespace aura {
@@ skipping 175 matching lines @@
 
   int thread_bundle_options_;
   scoped_ptr<TestBrowserThreadBundle> thread_bundle_;
 
   DISALLOW_COPY_AND_ASSIGN(RenderViewHostTestHarness);
 };
 
 }  // namespace content
 
 #endif  // CONTENT_PUBLIC_TEST_TEST_RENDERER_HOST_H_