Extract re-usable InitializeMediaFoundation()

media/base/win/mf_initializer.h

+// Copyright 2015 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 MEDIA_BASE_WIN_MF_INITIALIZER_H_
+#define MEDIA_BASE_WIN_MF_INITIALIZER_H_
+
+#include "media/base/media_export.h"
+
+namespace media {
+
+// Makes sure MFStartup() is called exactly once, and that this call is paired
+// by a call to MFShutdown().
+MEDIA_EXPORT void InitializeMediaFoundation();
+
+}  // namespace media
+
+#endif  // MEDIA_BASE_WIN_MF_INITIALIZER_H_