views: Move box_layout.[cc,h] into the new layout directory.

views/examples/widget_example.h

-// Copyright (c) 2010 The Chromium Authors. All rights reserved.
+// Copyright (c) 2011 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 VIEWS_EXAMPLES_WIDGET_EXAMPLE_H_
 #define VIEWS_EXAMPLES_WIDGET_EXAMPLE_H_
 #pragma once
 
 #include "views/background.h"
-#include "views/box_layout.h"
 #include "views/controls/button/text_button.h"
 #include "views/examples/example_base.h"
+#include "views/layout/box_layout.h"
 #include "views/view.h"
 #include "views/widget/root_view.h"
 #include "views/widget/widget.h"
 
 #if defined(OS_LINUX)
 #include "views/widget/widget_gtk.h"
 #endif
 
 namespace {
 
@@ skipping 161 matching lines @@
         break;
     }
   }
 
   DISALLOW_COPY_AND_ASSIGN(WidgetExample);
 };
 
 }  // namespace examples
 
 #endif  // VIEWS_EXAMPLES_WIDGET_EXAMPLE_H_