Summary:
Closes https://github.com/facebook/rocksdb/pull/575

I fixed the merge conflicts etc.
Closes https://github.com/facebook/rocksdb/pull/3065

Differential Revision: D7128233

Pulled By: sagar0

fbshipit-source-id: 2c23a48c9f0432c290b0cd16a12fb691bb37820c