Adds validation for various cases.

Adds corresponding unit tests.

Change-Id: I9451d286bcf2d6fa32de495e5d0bdec1eb5c955d
Reviewed-on: https://chromium-review.googlesource.com/633157Reviewed-by: Jamie Madill <jmadill@chromium.org>
Reviewed-by: Geoff Lang <geofflang@chromium.org>
Commit-Queue: Jamie Madill <jmadill@chromium.org>