Change ERR to WARN in RendererD3D::skipDraw For undefined behavior when point rendering without writing to gl_PointSize. Even the comment used to say "This is stictly speaking not an error". BUG=angleproject:1660 Change-Id: Ic8b33689151c9812592dd6b22c83a3355b7d6756 Reviewed-on: https://chromium-review.googlesource.com/437746 Reviewed-by: Jamie Madill <jmadill@chromium.org> Commit-Queue: Jamie Madill <jmadill@chromium.org>