Remove unused fields related to old multitexturing TextureOp.

Change-Id: I6a48410f2203a0a88831d02713b9b7475fb6e5a6
Reviewed-on: https://skia-review.googlesource.com/c/192826
Commit-Queue: Brian Salomon <bsalomon@google.com>
Commit-Queue: Brian Osman <brianosman@google.com>
Auto-Submit: Brian Salomon <bsalomon@google.com>
Reviewed-by: Brian Osman <brianosman@google.com>
2 files changed