Summary:
EncryptEnv class is both declared and defined within env_encryption.cc. This makes it really tough to derive new classes from that base.
This branch moves declaration of the class to rocksdb/env_encryption.h. The change facilitates making new encryption modules (such as an upcoming openssl AES CTR pull request) possible / easy.
The only coding change was to add the EncryptEnv object to env_basic_test.cc.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/6830
Reviewed By: riversand963
Differential Revision: D21706593
Pulled By: ajkr
fbshipit-source-id: 64d2da95a1569ceeb9b1549c3bec5404cf4c89f0