Code clean-up in AesDecryptor and test.

media/crypto/aes_decryptor.h

 // Copyright (c) 2012 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_CRYPTO_AES_DECRYPTOR_H_
 #define MEDIA_CRYPTO_AES_DECRYPTOR_H_
 
 #include <string>
 
 #include "base/basictypes.h"
@@ skipping 68 matching lines @@
 
     // The key used to perform the integrity check.  Currently the HMAC key is
     // defined by the WebM encrypted specification. Current encrypted WebM
     // request for comments specification is here
     // http://wiki.webmproject.org/encryption/webm-encryption-rfc
     std::string hmac_key_;
 
     DISALLOW_COPY_AND_ASSIGN(DecryptionKey);
   };
 
+  void SetKey(const std::string& key_id, scoped_ptr<DecryptionKey> key);

[ddorwin, 2012/07/26 21:24:07]

Should note that this object takes ownership of key.

[xhwang, 2012/07/26 23:36:47]

Since scopted_ptr<> is move only, by passing in a scoped_ptr<DecryptionKey>, the
AesDecryptor has to take the ownership or the key is released. But I agree a
comment is clearer. Done.

+  DecryptionKey* GetKey(const std::string& key_id) const;

[ddorwin, 2012/07/26 21:24:07]

Who owns the key? If it's not a copy, should that be a const ref? Might then
need a "null" DecryptionKey.

[xhwang, 2012/07/26 23:36:47]

Added a comment that the AesDecryptor still owns the key.

+
   // KeyMap owns the DecryptionKey* and must delete them when they are
   // not needed any more.
   typedef base::hash_map<std::string, DecryptionKey*> KeyMap;
 
   // Since only Decrypt() is called off the renderer thread, we only need to
   // protect |key_map_|, the only member variable that is shared between
   // Decrypt() and other methods.
   KeyMap key_map_;  // Protected by the |key_map_lock_|.
-  base::Lock key_map_lock_;  // Protects the |key_map_|.
+  mutable base::Lock key_map_lock_;  // Protects the |key_map_|.
 
   // Make session ID unique per renderer by making it static.
   // TODO(xhwang): Make session ID more strictly defined if needed:
   // https://www.w3.org/Bugs/Public/show_bug.cgi?id=16739#c0
   static uint32 next_session_id_;
 
   DecryptorClient* const client_;
 
   DISALLOW_COPY_AND_ASSIGN(AesDecryptor);
 };
 
 }  // namespace media
 
 #endif  // MEDIA_CRYPTO_AES_DECRYPTOR_H_