Use the block encoder class to store uniform offsets. This will allow us to use the same code path for assigning register information in all places. Because of this it fixes some long-broken dEQP struct uniform tests. BUG=angle:466 BUG=angle:505 Change-Id: I4161a388503aa09bbe2d21ff47bfb3352ec93881 Reviewed-on: https://chromium-review.googlesource.com/207255 Reviewed-by: Zhenyao Mo <zmo@chromium.org> Tested-by: Jamie Madill <jmadill@chromium.org> Reviewed-by: Nicolas Capens <capn@chromium.org>