It was skipping elementArrayBufferOverride->onReadResource()
if mCurrentElementArrayBufferResource was null.
BUG=angleproject:2389
Change-Id: If33a11d35225daf572796abc8c18f6d6df758b48
Reviewed-on: https://chromium-review.googlesource.com/989408
Commit-Queue: Frank Henigman <fjhenigman@chromium.org>
Reviewed-by: Luc Ferron <lucferron@chromium.org>
