If we can make the index range computation happen as late as possible,
we won't have to check it during the fastest draw call paths.

This change makes it easier to skip re-computing some index range
checks by only checking it in one place in IndexDataManager, and by
making it a lazy check; the check is never evaluated if the primitive
restart workaround is not enabled.

Future work can also push the index range computation for vertex info
later, so we only evaluate it in the cases where we need it.

BUG=angleproject:2229

Change-Id: Ic55fac9e23fd35a119ddff475355a43095d2e3e9
Reviewed-on: https://chromium-review.googlesource.com/764675
Commit-Queue: Jamie Madill <jmadill@chromium.org>
Reviewed-by: Yuly Novikov <ynovikov@chromium.org>
Reviewed-by: Geoff Lang <geofflang@chromium.org>