During draw calls, we wouldn't add the current attrib offset to the
required draw call size when checking attributes. This could lead to
us producing warnings in the D3D11 runtime, and miss returning some
errors.

Re-land with a test data initialization fix, and with some extra
tests merged from another CL.

BUG=angleproject:1339

Change-Id: Ifd549c3b1f6871417dc1693cb3ec534414e92cfd
Reviewed-on: https://chromium-review.googlesource.com/333723Reviewed-by: Jamie Madill <jmadill@chromium.org>
Commit-Queue: Jamie Madill <jmadill@chromium.org>