Add MediaKeySession.expiration attribute.

public/platform/WebContentDecryptionModuleSession.h

 /*
  * Copyright (C) 2013 Google 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:
  *
  *     * Redistributions of source code must retain the above copyright
  * notice, this list of conditions and the following disclaimer.
  *     * Redistributions in binary form must reproduce the above
@@ skipping 38 matching lines @@
             MediaKeyErrorCodeClient,
         };
 
         virtual void message(const unsigned char* message, size_t messageLength, const WebURL& destinationURL) = 0;
         virtual void ready() = 0;
         virtual void close() = 0;
         // FIXME: Remove this method once Chromium updated to use the new parameters.
         virtual void error(MediaKeyErrorCode, unsigned long systemCode) = 0;
         virtual void error(WebContentDecryptionModuleException, unsigned long systemCode, const WebString& message) = 0;
 
+        // Called when the expiration time for the session changes. |time| is
+        // specified as the number of milliseconds since 01 January, 1970 UTC.
+        virtual void expirationChanged(double updatedExpiryTimeInMS) = 0;
+
     protected:
         virtual ~Client();
     };
 
     virtual ~WebContentDecryptionModuleSession();
 
     virtual void setClientInterface(Client*) = 0;
     virtual WebString sessionId() const = 0;
 
     // FIXME: Remove these methods once the new methods are implemented in Chromium.
     virtual void initializeNewSession(const WebString& mimeType, const unsigned char* initData, size_t initDataLength) = 0;
     virtual void update(const unsigned char* response, size_t responseLength) = 0;
     virtual void release() = 0;
 
     virtual void initializeNewSession(const WebString& initDataType, const unsigned char* initData, size_t initDataLength, const WebString& sessionType, WebContentDecryptionModuleResult);
     virtual void update(const unsigned char* response, size_t responseLength, WebContentDecryptionModuleResult);
     virtual void release(WebContentDecryptionModuleResult);
 };
 
 } // namespace blink
 
 #endif // WebContentDecryptionModuleSession_h