The validation of the offsets parameter is added in this change.

Bug: angleproject:3569
Change-Id: Ide2ea4b9e88b28ca5ef34d5f3f5203f6e48d5f74
Reviewed-on: https://chromium-review.googlesource.com/c/angle/angle/+/1979133Reviewed-by: Shahbaz Youssefi <syoussefi@chromium.org>
Reviewed-by: Cody Northrop <cnorthrop@google.com>
Reviewed-by: Jiajia Qin <jiajia.qin@intel.com>
Commit-Queue: Shahbaz Youssefi <syoussefi@chromium.org>