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

ui/compositor/layer.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_COMPOSITOR_LAYER_H_
 #define UI_COMPOSITOR_LAYER_H_
 
 #include <string>
 #include <vector>
 
 #include "base/compiler_specific.h"
 #include "base/memory/ref_counted.h"
 #include "base/memory/scoped_ptr.h"
-#include "base/message_loop.h"
+#include "base/message_loop/message_loop.h"
 #include "cc/animation/animation_events.h"
 #include "cc/animation/layer_animation_event_observer.h"
 #include "cc/base/scoped_ptr_vector.h"
 #include "cc/layers/content_layer_client.h"
 #include "cc/layers/texture_layer_client.h"
 #include "cc/resources/texture_mailbox.h"
 #include "third_party/skia/include/core/SkColor.h"
 #include "third_party/skia/include/core/SkRegion.h"
 #include "ui/compositor/compositor.h"
 #include "ui/compositor/layer_animation_delegate.h"
@@ skipping 461 matching lines @@
   // The size of the delegated frame in DIP, set when SetDelegatedFrame was
   // called.
   gfx::Size delegated_frame_size_in_dip_;
 
   DISALLOW_COPY_AND_ASSIGN(Layer);
 };
 
 }  // namespace ui
 
 #endif  // UI_COMPOSITOR_LAYER_H_