If uniform block is translated to StructureBuffer on D3D backend, must do a GPU-GPU copy when updating uniform buffer. If buffer's latest usage is StructuredBuffer, directly upload to structured buffer. Bug: angleproject:3682 Change-Id: I7303866d08705a43238732e5f5ae4858f0a33d63 Reviewed-on: https://chromium-review.googlesource.com/c/angle/angle/+/2131871 Commit-Queue: Xinghua Cao <xinghua.cao@intel.com> Reviewed-by: Jiajia Qin <jiajia.qin@intel.com> Reviewed-by: Jamie Madill <jmadill@chromium.org> Reviewed-by: Kenneth Russell <kbr@chromium.org>
