DO NOT MERGE ANYWHERE: BufferQueue consumers: Add discardFreeBuffer method am: 8211047138  -s ours am: 7b265d8ab5  -s ours am: e373a97bd7  -s ours
am: 3f3171788d  -s ours

Change-Id: I9a9797580b99e5f529302220e437dc288e3afb36