Add widevine third party

Add 2 new command options to use widevine:
- widevine-cdm-path: Path to widevine plugin
- widevine-cdm-version: Version of the widevine plugin

chromium_src/chrome/renderer/media/chrome_key_systems.h

@@ -0,0 +1,14 @@
+// Copyright 2013 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 CHROME_RENDERER_MEDIA_CHROME_KEY_SYSTEMS_H_
+#define CHROME_RENDERER_MEDIA_CHROME_KEY_SYSTEMS_H_
+
+#include <vector>
+
+#include "media/base/key_system_info.h"
+
+void AddChromeKeySystems(std::vector<media::KeySystemInfo>* key_systems_info);
+
+#endif  // CHROME_RENDERER_MEDIA_CHROME_KEY_SYSTEMS_H_