Remove generic GrFragmentProcessor texture sampling.

Instead GrTextureEffect is a special effect known by
program builders, pipeline states, etc.

Change-Id: I4436d7a10a1c3174fe1f02f136363a1c117f92fb
Reviewed-on: https://skia-review.googlesource.com/c/skia/+/301357
Reviewed-by: Greg Daniel <egdaniel@google.com>
Commit-Queue: Brian Salomon <bsalomon@google.com>
diff --git a/src/gpu/GrPipeline.h b/src/gpu/GrPipeline.h
index a59adde..11eb8b0 100644
--- a/src/gpu/GrPipeline.h
+++ b/src/gpu/GrPipeline.h
@@ -113,6 +113,8 @@
     }
     int numFragmentProcessors() const { return fFragmentProcessors.count(); }
 
+    void visitTextureEffects(const std::function<void(const GrTextureEffect&)>&) const;
+
     const GrXferProcessor& getXferProcessor() const {
         if (fXferProcessor) {
             return *fXferProcessor.get();