Some test cases use wrong barriers when calling glMemoryBarrier.

Bug: angleproject:2280
Change-Id: I0750c1eba84ed8af32091f7ecd5bdbd2b32fd397
Reviewed-on: https://chromium-review.googlesource.com/c/angle/angle/+/1687591Reviewed-by: Jiajia Qin <jiajia.qin@intel.com>
Reviewed-by: Shahbaz Youssefi <syoussefi@chromium.org>
Commit-Queue: Xinghua Cao <xinghua.cao@intel.com>