HandleAllocator: make HandleRange inclusive. 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/399565 Reviewed-by: Zhenyao Mo <zmo@chromium.org> Reviewed-by: Corentin Wallez <cwallez@chromium.org> Commit-Queue: Corentin Wallez <cwallez@chromium.org>