applyShaders will update uniform data by uploading the constant buffer.
In the future uniform data will contain the base level of textures so
that shaders can use it to adjust results of texture functions. The most
natural place to set the base level in uniform data is applyTextures, so
it needs to be run before applyShaders.

updateSamplerMapping needs to be called before applyTextures, but
genericDraw* functions already do that. Remove redundant
updateSamplerMapping call from ProgramD3D::applyUniforms.

BUG=angleproject:596
BUG=angleproject:1092
BUG=angleproject:1261
TEST=angle_end2end_tests

Change-Id: I1828f7bdc75999872a26941a02cb4b6c6a66094d
Reviewed-on: https://chromium-review.googlesource.com/322121Reviewed-by: Jamie Madill <jmadill@chromium.org>
Tryjob-Request: Olli Etuaho <oetuaho@nvidia.com>
Tested-by: Olli Etuaho <oetuaho@nvidia.com>
Reviewed-by: Geoff Lang <geofflang@chromium.org>