Our recommendation to OEMs is that they support a table of at least 50
usage entries in OEMCrypto. If more usage entries are stored, the PSTs get
added to the CDM but are LRU'ed out of the OEMCrypto usage table. When the
CDM queries those usage entries, OEMCrypto will return a
OEMCrypto_ERROR_INVALID_CONTEXT. Rather than return an error and have
MediaDrm throw an exception, CDM should delete this PST and return the
next usage entry, when queried.
[ Merge of https://widevine-internal-review.googlesource.com/#/c/11457/
from Widevine cdm repo ]
b/17994711
Change-Id: I00e3f93000096fb434d94333e22958de795a4bb5