These cases were unreachable.

BUG=angleproject:1455

Change-Id: I5f3b969de3aca3862944ac9ed510c9f5e9fd77e2
Reviewed-on: https://chromium-review.googlesource.com/367695
Commit-Queue: Jamie Madill <jmadill@chromium.org>
Reviewed-by: Geoff Lang <geofflang@chromium.org>