Enable asserts about 'in' and 'uniform' in GrSkSLFP and ByteCode

Change-Id: I2bbef8af07f9a65c7a6577a00b1eb7a47c252f57
Reviewed-on: https://skia-review.googlesource.com/c/skia/+/245617
Commit-Queue: Brian Osman <brianosman@google.com>
Reviewed-by: Ethan Nicholas <ethannicholas@google.com>
diff --git a/src/sksl/SkSLByteCodeGenerator.cpp b/src/sksl/SkSLByteCodeGenerator.cpp
index 6c8dab4..f0e4ef5 100644
--- a/src/sksl/SkSLByteCodeGenerator.cpp
+++ b/src/sksl/SkSLByteCodeGenerator.cpp
@@ -74,7 +74,7 @@
                     // should either specialize the program (Compiler::specialize) to bake in the
                     // final values of the 'in' variables, or not use 'in' variables (maybe you
                     // meant to use 'uniform' instead?).
-//                    SkASSERT(!(declVar->fModifiers.fFlags & Modifiers::kIn_Flag));
+                    SkASSERT(!(declVar->fModifiers.fFlags & Modifiers::kIn_Flag));
                     if (is_uniform(*declVar)) {
                         fOutput->fUniformSlotCount += SlotCount(declVar->fType);
                     } else {