Extract re-usable InitializeMediaFoundation()

media/base/win/mf_initializer.cc

+// 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.
+
+#include "media/base/win/mf_initializer.h"
+
+#include <mfapi.h>
+
+#include "base/lazy_instance.h"
+#include "base/macros.h"
+
+namespace media {
+
+namespace {
+
+// LazyInstance to initialize the Media Foundation Library.
+class MFInitializer {
+ public:
+  MFInitializer()
+      : mf_started_(MFStartup(MF_VERSION, MFSTARTUP_LITE) == S_OK) {}
+
+  ~MFInitializer() {
+    if (mf_started_)
+      MFShutdown();
+  }
+
+ private:
+  const bool mf_started_;
+
+  DISALLOW_COPY_AND_ASSIGN(MFInitializer);
+};
+
+base::LazyInstance<MFInitializer> g_mf_initializer = LAZY_INSTANCE_INITIALIZER;
+
+}  // namespace
+
+void EnsureMediaFoundationInitialized() {
+  g_mf_initializer.Get();
+}
+
+}  // namespace media