Doesn't take encryptor param any more.

Chromium change:

https://chromium.googlesource.com/chromium/src/+/b0294c676cb8fe3a75b26e098b15b37156e48912

commit b0294c676cb8fe3a75b26e098b15b37156e48912
Author: Maksim Moskvitin <mmoskvitin@google.com>
Date:   Mon Jul 15 17:40:20 2019 +0000

    [Sync] Remove encryptor_ member from Cryptographer

    The only reason to have Encryptor dependency inside Cryptographer is
    methods related to so-called bootstrap token. They provide logic
    related to persistence of custom passphrase keys and strictly don't
    seem to belong Cryptographer level. While we can't factor them out
    right now, because it would mean intrusive and big changes in Directory
    codepath, we reduce this dependency by replacing |encryptor_| member in
    Cryptographer class with |encryptor| parameter in corresponding methods
    family. It allows to simplify significant amount of code, related to
    plumbing Encryptor, while it's actually not needed.

    Bug: 967417