Adds a gfx_export.h to ui/gfx and converts all code in ui/gfx to

ui/gfx/image/image_family.h

 // Copyright 2013 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_GFX_IMAGE_IMAGE_FAMILY_H_
 #define UI_GFX_IMAGE_IMAGE_FAMILY_H_
 
 #include <iterator>
 #include <map>
 #include <utility>
 
-#include "ui/base/ui_export.h"
+#include "ui/gfx/gfx_export.h"
 #include "ui/gfx/image/image.h"
 
 namespace gfx {
 class ImageSkia;
 class Size;
 
 // A collection of images at different sizes. The images should be different
 // representations of the same basic concept (for example, an icon) at various
 // sizes and (optionally) aspect ratios. A method is provided for finding the
 // most appropriate image to fit in a given rectangle.
@@ skipping 124 matching lines @@
   // |map_| of aspect ratio |aspect|.
   const gfx::Image* GetWithExactAspect(float aspect, int width) const;
 
   // Map from (aspect ratio, width) to image.
   std::map<MapKey, gfx::Image> map_;
 };
 
 }  // namespace gfx
 
 #endif  // UI_GFX_IMAGE_IMAGE_FAMILY_H_