[encrypted-media] Ensure message type is correct for loaded sessions

ddorwin has just created a new issue for
https://github.com/w3c/encrypted-media:

== Ensure message type is correct for loaded sessions ==
[Bug 27111](https://www.w3.org/Bugs/Public/show_bug.cgi?id=27111)
split the persistent session type in two, but the `load()` algorithm
does not ensure that the type the session was originally created with
matches the type of session into which it was loaded. In addition to
correctness, this will be important when #16 is resolved and the
algorithms behave differently depending on the session type.

The best and simplest option is to update the the `load()` algorithm
to ensure that the (new) `MediaKeySession` object was created
(`createSession()`) with the correct/matching type. This ensures that
the application knows what behavior to expect. This should be
reasonable for most applications since they are unlikely to mix the
two types of "persistent-" sessions.

See https://github.com/w3c/encrypted-media/issues/20

Received on Wednesday, 21 January 2015 00:26:24 UTC