[eme] Handle multiple calls to MediaKeySession.close()

media/cdm/aes_decryptor.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_AES_DECRYPTOR_H_
 #define MEDIA_CDM_AES_DECRYPTOR_H_
 
 #include <stdint.h>
 
 #include <memory>
@@ skipping 128 matching lines @@
   SessionMessageCB session_message_cb_;
   SessionClosedCB session_closed_cb_;
   SessionKeysChangeCB session_keys_change_cb_;
 
   // 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.
   KeyIdToSessionKeysMap key_map_;  // Protected by |key_map_lock_|.
   mutable base::Lock key_map_lock_;  // Protects the |key_map_|.
 
-  // Keeps track of current valid sessions.
-  std::set<std::string> valid_sessions_;
+  // Keeps track of current open sessions.
+  std::set<std::string> open_sessions_;
 
   // Make session ID unique per renderer by making it static. Session
   // IDs seen by the app will be "1", "2", etc.
   static uint32_t next_session_id_;
 
   NewKeyCB new_audio_key_cb_;
   NewKeyCB new_video_key_cb_;
 
   // Protect |new_audio_key_cb_| and |new_video_key_cb_| as they are set on the
   // main thread but called on the media thread.
   mutable base::Lock new_key_cb_lock_;
 
   DISALLOW_COPY_AND_ASSIGN(AesDecryptor);
 };
 
 }  // namespace media
 
 #endif  // MEDIA_CDM_AES_DECRYPTOR_H_