Create a Factory for NativeMetafile.

printing/native_metafile_factory.cc

+// 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.
+
+#include "printing/native_metafile_factory.h"
+
+namespace printing {
+
+// static
+printing::NativeMetafile* NativeMetafileFactory::CreateMetafile() {
+#if defined(OS_WIN)
+  return new printing::Emf;
+#elif defined(OS_MACOSX)
+  return new printing::PdfMetafile;
+#elif defined(OS_POSIX)
+  return new printing::PdfPsMetafile;
+#endif
+}
+
+}  // namespace printing