Remove un-needed LimitingReader read() function.

We only need one read function here.

Change-Id: I86533399d33fd5784b8b942acf37ea5c42363236
Clean up duplicate methods

The identity.core.Driver class had a few function definitions
with the same name. Remove duplicates because it's confusing.

Change-Id: I9e4ca8939414091acc0c0eedaf64960a2fb9dad3
Merge "Remove un-needed LimitingReader read() function."
Merge "Clean up duplicate methods"