Shadow samplers use a different sampler object type in D3D11 HLSL than other ESSL samplers. They need to be able to coexist in the same shader. BUG=angleproject:1261 TEST=angle_end2end_tests Change-Id: I960f6a41c0237ed912b072527e14aebeca98cf7c Reviewed-on: https://chromium-review.googlesource.com/322120 Tryjob-Request: Olli Etuaho <oetuaho@nvidia.com> Tested-by: Olli Etuaho <oetuaho@nvidia.com> Reviewed-by: Jamie Madill <jmadill@chromium.org> Reviewed-by: Zhenyao Mo <zmo@chromium.org>
