Add printing.dll to the component build.

printing/metafile_skia_wrapper.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_METAFILE_SKIA_WRAPPER_H_
 #define PRINTING_METAFILE_SKIA_WRAPPER_H_
 
+#include "printing/printing_export.h"
 #include "third_party/skia/include/core/SkRefCnt.h"
 
 class SkCanvas;
 
 namespace printing {
 
 class Metafile;
 
 // A wrapper class with static methods to set and retrieve a Metafile
 // on an SkCanvas.  The ownership of the metafile is not affected and it
 // is the caller's responsibility to ensure that the metafile remains valid
 // as long as the canvas.
-class MetafileSkiaWrapper : public SkRefCnt {
+class PRINTING_EXPORT MetafileSkiaWrapper : public SkRefCnt {
  public:
   static void SetMetafileOnCanvas(SkCanvas* canvas, Metafile* metafile);
 
   static Metafile* GetMetafileFromCanvas(SkCanvas* canvas);
 
   static void SetDraftMode(SkCanvas* canvas, bool draft_mode);
 
   static bool GetDraftMode(SkCanvas* canvas);
 
  private:
   explicit MetafileSkiaWrapper(Metafile* metafile);
 
   Metafile* metafile_;
 };
 
 }  // namespace printing
 
 #endif  // PRINTING_METAFILE_SKIA_WRAPPER_H_