EME: close() should return a resolved promise if session already closed

third_party/WebKit/Source/modules/encryptedmedia/MediaKeySession.cpp

 /*
  * Copyright (C) 2013 Apple Inc. All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions
  * are met:
  * 1. Redistributions of source code must retain the above copyright
  *    notice, this list of conditions and the following disclaimer.
  * 2. Redistributions in binary form must reproduce the above copyright
  *    notice, this list of conditions and the following disclaimer in the
@@ skipping 744 matching lines @@
 
   // From https://w3c.github.io/encrypted-media/#close:
   // Indicates that the application no longer needs the session and the CDM
   // should release any resources associated with the session and close it.
   // Persisted data should not be released or cleared.
   // When this method is invoked, the user agent must run the following steps:
 
   // 1. Let session be the associated MediaKeySession object.
   // 2. If session is closed, return a resolved promise.
   if (m_isClosed)
-    return ScriptPromise::cast(scriptState, ScriptValue());
+    return ScriptPromise::castUndefined(scriptState);
 
   // 3. If session's callable value is false, return a promise rejected with
   //    an InvalidStateError.
   if (!m_isCallable)
     return CreateRejectedPromiseNotCallable(scriptState);
 
   // 4. Let promise be a new promise.
   SimpleResultPromise* result = new SimpleResultPromise(scriptState, this);
   ScriptPromise promise = result->promise();
 
@@ skipping 269 matching lines @@
   visitor->trace(m_asyncEventQueue);
   visitor->trace(m_pendingActions);
   visitor->trace(m_mediaKeys);
   visitor->trace(m_keyStatusesMap);
   visitor->trace(m_closedPromise);
   EventTargetWithInlineData::trace(visitor);
   ContextLifecycleObserver::trace(visitor);
 }
 
 }  // namespace blink