Stop aggregating texture/buffer access objects in GrFragmentProcessor parents.

BUG=skia:
GOLD_TRYBOT_URL= https://gold.skia.org/search?issue=2349243002

Review-Url: https://codereview.chromium.org/2365943003
diff --git a/src/effects/gradients/SkGradientShader.cpp b/src/effects/gradients/SkGradientShader.cpp
index d625d8e..31ff9ab 100644
--- a/src/effects/gradients/SkGradientShader.cpp
+++ b/src/effects/gradients/SkGradientShader.cpp
@@ -1248,7 +1248,7 @@
                                                 const char* gradientTValue,
                                                 const char* outputColor,
                                                 const char* inputColor,
-                                                const SamplerHandle* texSamplers) {
+                                                const TextureSamplers& texSamplers) {
     switch (ge.getColorType()) {
 #if GR_GL_USE_ACCURATE_HARD_STOP_GRADIENTS
         case kHardStopCentered_ColorType: {