Revert "Support precision emulation on HLSL" Forgot to add virtual destructors. BUG=angleproject:1437 This reverts commit a42e8b2cb9d0857f53c0490b5be3bf25b4e1f827. Change-Id: If33fecfeca9947deedf4668c64dbadf25a5dc5eb Reviewed-on: https://chromium-review.googlesource.com/360122 Reviewed-by: Olli Etuaho <oetuaho@nvidia.com>