Add MediaKeySession.expiration attribute.

Source/modules/encryptedmedia/MediaKeySession.h

 /*
  * 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 52 matching lines @@
     , private WebContentDecryptionModuleSession::Client {
     DEFINE_EVENT_TARGET_REFCOUNTING_WILL_BE_REMOVED(RefCountedGarbageCollected<MediaKeySession>);
     DEFINE_WRAPPERTYPEINFO();
     WILL_BE_USING_GARBAGE_COLLECTED_MIXIN(MediaKeySession);
 public:
     static MediaKeySession* create(ScriptState*, MediaKeys*, const String& sessionType);
     virtual ~MediaKeySession();
 
     const String& keySystem() const { return m_keySystem; }
     String sessionId() const;
+    double expiration() const { return m_expiration; }
     ScriptPromise closed(ScriptState*);
 
     ScriptPromise generateRequest(ScriptState*, const String& initDataType, ArrayBuffer* initData);
     ScriptPromise generateRequest(ScriptState*, const String& initDataType, ArrayBufferView* initData);
 
     void setError(MediaKeyError*);
     MediaKeyError* error() { return m_error.get(); }
 
     ScriptPromise update(ScriptState*, ArrayBuffer* response);
     ScriptPromise update(ScriptState*, ArrayBufferView* response);
@@ skipping 36 matching lines @@
     String m_keySystem;
     RefPtrWillBeMember<MediaKeyError> m_error;
     OwnPtrWillBeMember<GenericEventQueue> m_asyncEventQueue;
     OwnPtr<WebContentDecryptionModuleSession> m_session;
 
     // Used to determine if MediaKeys is still active.
     WeakMember<MediaKeys> m_mediaKeys;
 
     // Session properties.
     String m_sessionType;
+    double m_expiration;
 
     // Session states.
     bool m_isUninitialized;
     bool m_isCallable;
     bool m_isClosed; // Is the CDM finished with this session?
 
     // Keep track of the closed promise.
     typedef ScriptPromiseProperty<Member<MediaKeySession>, V8UndefinedType, RefPtrWillBeMember<DOMException> > ClosedPromise;
     Member<ClosedPromise> m_closedPromise;
 
     HeapDeque<Member<PendingAction> > m_pendingActions;
     Timer<MediaKeySession> m_actionTimer;
 };
 
 } // namespace blink
 
 #endif // MediaKeySession_h