Make SkSL CPP code gen copy explicit coord status for cloned FPs

Change-Id: I1479136de8fcab32e2be661fd5fae020b319aab8
Reviewed-on: https://skia-review.googlesource.com/c/skia/+/272458
Commit-Queue: Brian Salomon <bsalomon@google.com>
Reviewed-by: Brian Osman <brianosman@google.com>
diff --git a/src/gpu/effects/generated/GrMixerEffect.cpp b/src/gpu/effects/generated/GrMixerEffect.cpp
index e64c857..54ae337 100644
--- a/src/gpu/effects/generated/GrMixerEffect.cpp
+++ b/src/gpu/effects/generated/GrMixerEffect.cpp
@@ -68,9 +68,17 @@
         , fp0_index(src.fp0_index)
         , fp1_index(src.fp1_index)
         , weight(src.weight) {
-    this->registerChildProcessor(src.childProcessor(fp0_index).clone());
+    {
+        auto clone = src.childProcessor(fp0_index).clone();
+        clone->setSampledWithExplicitCoords(
+                src.childProcessor(fp0_index).isSampledWithExplicitCoords());
+        this->registerChildProcessor(std::move(clone));
+    }
     if (fp1_index >= 0) {
-        this->registerChildProcessor(src.childProcessor(fp1_index).clone());
+        auto clone = src.childProcessor(fp1_index).clone();
+        clone->setSampledWithExplicitCoords(
+                src.childProcessor(fp1_index).isSampledWithExplicitCoords());
+        this->registerChildProcessor(std::move(clone));
     }
 }
 std::unique_ptr<GrFragmentProcessor> GrMixerEffect::clone() const {