8c81d38a73
(This is a merge of http://go/wvgerrit/14242) To try to fix b/17761616, I added a lock to the DRM Plugin. However, the API guarantees that any single DrmPlugin will never be called into from multiple threads at the same time, rendering this unnecessary. Previously, b/18194977 meant that this was not always true, but now that that bug is fixed, this lock is not needed and can be removed. Bug: 18194977 Change-Id: I25ee5fa44f35706f863b036997453441eac29c95