media: Move key_system_names to media/base/

media/cdm/key_system_names.h

-// 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 MEDIA_CDM_KEY_SYSTEM_NAMES_H_
-#define MEDIA_CDM_KEY_SYSTEM_NAMES_H_
-
-#include <string>
-
-#include "media/base/media_export.h"
-
-namespace media {
-
-// TODO(jrummell): Change other uses of Clear Key to use this common value.
-
-// The key system name for Clear Key.
-MEDIA_EXPORT extern const char kClearKey[];
-
-// The key system name for External Clear Key.
-MEDIA_EXPORT extern const char kExternalClearKey[];
-
-// Returns true if |key_system| is Clear Key, false otherwise.
-MEDIA_EXPORT bool IsClearKey(const std::string& key_system);
-
-// Returns true if |key_system| is (reverse) sub-domain of |base|.
-MEDIA_EXPORT bool IsChildKeySystemOf(const std::string& key_system,
-                                     const std::string& base);
-
-// Returns true if |key_system| is External Clear Key, false otherwise.
-MEDIA_EXPORT bool IsExternalClearKey(const std::string& key_system);
-
-}  // namespace media
-
-#endif  // MEDIA_CDM_KEY_SYSTEM_NAMES_H_