This patch adds the support of the parameter 'baseVertex' of drawIndexed
on D3D12, Metal and Vulkan back-ends.
BUG=dawn:51
TEST=dawn_end2end_tests
Change-Id: Ibd25884ad2abceaaed744d74c4ee6b0ae6b3fa1b
Reviewed-on: https://dawn-review.googlesource.com/c/3221
Commit-Queue: Jiawei Shao <jiawei.shao@intel.com>
Reviewed-by: Kai Ninomiya <kainino@chromium.org>