Remove findSuccOffsets from translateRegion.

Summary: It's dead.

Reviewed By: @jdelong

Differential Revision: D1653846

Signature: t1:1653846:1414803027:bf2fba4cd13b3ba8ca99b2547e6573d6d0a628de
Trailing spaces and comment fixups.

Reviewed By: @elgenie

Differential Revision: D1654554

Signature: t1:1654554:1415004436:f0364eb5296cbadc823ce9b34e56ef5740ed1d95