Uncovered this after reports to the Google group.
Also fix a minor documentation issue with Windows store.

BUG=angleproject:1944
BUG=angleproject:1255

Change-Id: Ib4fc784a818cf65e280630db483987cc01366994
Reviewed-on: https://chromium-review.googlesource.com/657881Reviewed-by: Jamie Madill <jmadill@chromium.org>