This simply translates the offset qualifier and synchronizes
the buffer binding state for GL translator and renderer.

BUG=angleproject:1729
TEST=angle_end2end_tests:AtomicCounterBufferTest31

Change-Id: Ib8424918478ae4c47049d5856ea20ef022f12913
Reviewed-on: https://chromium-review.googlesource.com/575913
Commit-Queue: Geoff Lang <geofflang@chromium.org>
Reviewed-by: Corentin Wallez <cwallez@chromium.org>
Reviewed-by: Geoff Lang <geofflang@chromium.org>