EME: Remove reference to "concrete" key systems.

media/base/key_systems.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_BASE_KEY_SYSTEMS_H_
 #define MEDIA_BASE_KEY_SYSTEMS_H_
 
 #include <stdint.h>
 
 #include <string>
@@ skipping 62 matching lines @@
 // TODO(ddorwin): WebContentDecryptionModuleSessionImpl::initializeNewSession()
 // is violating this rule! https://crbug.com/249976.
 // Use for prefixed EME only!
 MEDIA_EXPORT bool IsSupportedKeySystemWithInitDataType(
     const std::string& key_system,
     EmeInitDataType init_data_type);
 
 // Returns a name for |key_system| suitable to UMA logging.
 MEDIA_EXPORT std::string GetKeySystemNameForUMA(const std::string& key_system);
 
-// Returns whether AesDecryptor can be used for the given |concrete_key_system|.
-MEDIA_EXPORT bool CanUseAesDecryptor(const std::string& concrete_key_system);
+// Returns whether AesDecryptor can be used for the given |key_system|.
+MEDIA_EXPORT bool CanUseAesDecryptor(const std::string& key_system);
 
 #if defined(ENABLE_PEPPER_CDMS)
-// Returns the Pepper MIME type for |concrete_key_system|.
-// Returns empty string if |concrete_key_system| is unknown or not Pepper-based.
-MEDIA_EXPORT std::string GetPepperType(
-    const std::string& concrete_key_system);
+// Returns the Pepper MIME type for |key_system|.
+// Returns empty string if |key_system| is unknown or not Pepper-based.
+MEDIA_EXPORT std::string GetPepperType(const std::string& key_system);
 #endif
 
 #if defined(UNIT_TEST)
 // Helper functions to add container/codec types for testing purposes.
 // Call AddCodecMask() first to ensure the mask values passed to
 // AddMimeTypeCodecMask() already exist.
 MEDIA_EXPORT void AddCodecMask(EmeMediaType media_type,
                                const std::string& codec,
                                uint32_t mask);
 MEDIA_EXPORT void AddMimeTypeCodecMask(const std::string& mime_type,
                                        uint32_t mask);
 #endif  // defined(UNIT_TEST)
 
 }  // namespace media
 
 #endif  // MEDIA_BASE_KEY_SYSTEMS_H_