(This is a merge of http://go/wvgerrit/92191)
This reverts commit 8fe569cc1265021e275a9bccbc362ebd2ba3be5f.
The ISO-CENC spec is ambiguous about how to handle the early truncation
of the pattern in the 'cens' and 'cbcs' schema. We originally
interpreted it to mean "follow the pattern until you run out of full
crypto blocks" and shipped the Android and OEMCrypto code accordingly.
Later, however, other engineers at Google asserted that it should mean
"follow the pattern until you run out of enough crypto blocks to follow
the encrypted part of the pattern", which is subtly different when the
number of encrypted blocks in the pattern is greater than 1. We made
changes to start accommodating this. However, after further discussion,
everyone is in agreement that the original behavior was correct. So I am
reverting the "fixes" that had already been made.
This has no practical effect, since it only affects 'cens' content with
a pattern that has more than one encrypted block, and as far as we know,
no one has ever generated content like that. Shaka Packager is not
capable of generating content like that.
Bug: 111001481
Test: No new Android Unit Tests failures
Change-Id: I8f0292b1222d6af9a0ae33d6cb91707fd40101f4
169c5b3d10