Remove ability to sample textures in vertex or geometry shaders.

Bug: skia:
Change-Id: I69cd07a4bbe4879e855fb4aa6289a049adf4e059
Reviewed-on: https://skia-review.googlesource.com/c/160021
Commit-Queue: Greg Daniel <egdaniel@google.com>
Reviewed-by: Chris Dalton <csmartdalton@google.com>
21 files changed