This patch enables several SSBO tests on D3D11 in ANGLE end2end
tests.

Bug: angleproject:1951
Change-Id: I1ba78133e5bbe581e8330c1c43755c174e28bf39
Reviewed-on: https://chromium-review.googlesource.com/c/1415721Reviewed-by: Jiajia Qin <jiajia.qin@intel.com>
Reviewed-by: Jamie Madill <jmadill@chromium.org>
Commit-Queue: Jiawei Shao <jiawei.shao@intel.com>