moved SkSL Extension data into IRNode

Change-Id: I6689bfc78e407ddd840d81ea56c844da92f3a65a
Reviewed-on: https://skia-review.googlesource.com/c/skia/+/320724
Commit-Queue: Ethan Nicholas <ethannicholas@google.com>
Reviewed-by: John Stiles <johnstiles@google.com>
diff --git a/src/sksl/SkSLMetalCodeGenerator.cpp b/src/sksl/SkSLMetalCodeGenerator.cpp
index a169144..4542518 100644
--- a/src/sksl/SkSLMetalCodeGenerator.cpp
+++ b/src/sksl/SkSLMetalCodeGenerator.cpp
@@ -73,7 +73,7 @@
 }
 
 void MetalCodeGenerator::writeExtension(const Extension& ext) {
-    this->writeLine("#extension " + ext.fName + " : enable");
+    this->writeLine("#extension " + ext.name() + " : enable");
 }
 
 String MetalCodeGenerator::typeName(const Type& type) {