Summary: Unconditionally execute the action, passthrough semantics.

Test Plan: new unit test

Reviewed By: bmatheny@fb.com

Subscribers: trunkagent, exa, folly-diffs@, yfeldblum, jsedgwick

FB internal diff: D1868837

Tasks: 6166860

Signature: t1:1868837:1424820181:0e83f54b59d7091dac60ab65feb387992e8ae89c