This introduces two new methods to `ToneMapper`: `isOneDimensional()` and
`isLDR()`. `ColorGrading` references these values along with other parameters
passed to the builder to determine if we can get away with only generating a
one-dimensional LUT. Meanwhile, `PostProcessManager` takes care of setting the
new spec constants and uniforms for `colorGrading.mat` and
`colorGradingAsSubpass.mat`.
Eliza Velasquez
4fbfd1b8c1