Add printing.dll to the component build.

printing/image.h

 // 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 PRINTING_IMAGE_H_
 #define PRINTING_IMAGE_H_
 
 #include <string>
 #include <vector>
 
 #include "base/basictypes.h"
 #include "base/logging.h"
+#include "printing/printing_export.h"
 #include "ui/gfx/size.h"
 
 class FilePath;
 
 namespace printing {
 
 class Metafile;
 
 // Lightweight raw-bitmap management. The image, once initialized, is immutable.
 // The main purpose is testing image contents.
-class Image {
+class PRINTING_EXPORT Image {
  public:
   // Creates the image from the given file on disk.  Uses extension to
   // defer file type. PNG and EMF (on Windows) currently supported.
   // If image loading fails size().IsEmpty() will be true.
   explicit Image(const FilePath& path);
 
   // Creates the image from the metafile.  Deduces bounds based on bounds in
   // metafile.  If loading fails size().IsEmpty() will be true.
   explicit Image(const Metafile& metafile);
 
@@ skipping 55 matching lines @@
   // Flag to signal if the comparison functions should ignore the alpha channel.
   const bool ignore_alpha_;  // Currently always true.
 
   // Prevent operator= (this function has no implementation)
   Image& operator=(const Image& image);
 };
 
 }  // namespace printing
 
 #endif  // PRINTING_IMAGE_H_