Previously part of the code saw it as [begin, end) while others saw it
as [begin, end].

BUG=angleproject:1052
BUG=chromium:656485

Change-Id: Id8e9e26b167e02a07dfc5341569df53a14d0623d
Reviewed-on: https://chromium-review.googlesource.com/399565Reviewed-by: Zhenyao Mo <zmo@chromium.org>
Reviewed-by: Corentin Wallez <cwallez@chromium.org>
Commit-Queue: Corentin Wallez <cwallez@chromium.org>