Fix crash in WV_Teardown() causes by deleting shared output parser object.
We used to have a single output parser object and a single memory chunk object
that are shared by multiple sessions. When we delete the output parser, another
session may still be using it. The deletion causes a native crash intermittently.
The fix addresses these two issues: i)output parser object is now created per
session, and ii)add reference count to keep track of the single memory chunk
object use so we do not delet it while other sessions are still using it.
Merge of https://widevine-internal-review.googlesource.com/#/c/9253/ and
https://widevine-internal-review.googlesource.com/#/c/9271/ from widevine repo
RC/4.5.0/601_AndroidOS_K branch.
Change-Id: I7ce467a514904c9087f0da5cea74e4b85fcac1b3
related-to-bug: 13208359
