Act on TODO: rename getRevision to getRevisionId

Change-Id: Ifd2885d5991dd93ee47a7212e635545b3962163a
Make stuff in CachingEntityRevisionLookup private

Change-Id: I4aa42518308c641b2d90c775c0c5c39afbdd01cb
Merge "Act on TODO: rename getRevision to getRevisionId"
Merge "Make stuff in CachingEntityRevisionLookup private"