Add printing.dll to the component build.

printing/metafile.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_H_
 #define PRINTING_METAFILE_H_
 
 #include "base/basictypes.h"
 #include "build/build_config.h"
+#include "printing/printing_export.h"
 #include "ui/gfx/native_widget_types.h"
 
 #if defined(OS_WIN)
 #include <windows.h>
 #elif defined(OS_MACOSX)
 #include <ApplicationServices/ApplicationServices.h>
 #include <CoreFoundation/CoreFoundation.h>
 #include "base/mac/scoped_cftyperef.h"
 #endif
 
@@ skipping 10 matching lines @@
 #if defined(OS_CHROMEOS)
 namespace base {
 struct FileDescriptor;
 }
 #endif
 
 namespace printing {
 
 // This class creates a graphics context that renders into a data stream
 // (usually PDF or EMF).
-class Metafile {
+class PRINTING_EXPORT Metafile {
  public:
   virtual ~Metafile() {}
 
   // Initializes a fresh new metafile for rendering. Returns false on failure.
   // Note: It should only be called from within the renderer process to allocate
   // rendering resources.
   virtual bool Init() = 0;
 
   // Initializes the metafile with the data in |src_buffer|. Returns true
   // on success.
@@ skipping 90 matching lines @@
   // Saves the underlying data to the file associated with fd. This function
   // should ONLY be called after the metafile is closed.
   // Returns true if writing succeeded.
   virtual bool SaveToFD(const base::FileDescriptor& fd) const = 0;
 #endif  // if defined(OS_CHROMEOS)
 };
 
 }  // namespace printing
 
 #endif  // PRINTING_METAFILE_H_