Revert of SkSL performance improvements

src/sksl/ir/SkSLField.h

Index: src/sksl/ir/SkSLField.h
diff --git a/src/sksl/ir/SkSLField.h b/src/sksl/ir/SkSLField.h
index a01df2943d0d4a797bf7231b6347e31d9895e462..f2b68bc2bcae4567967a829e96e104cf7b38ed48 100644
--- a/src/sksl/ir/SkSLField.h
+++ b/src/sksl/ir/SkSLField.h
@@ -21,16 +21,16 @@
  * result of declaring anonymous interface blocks.
  */
 struct Field : public Symbol {
-    Field(Position position, const Variable& owner, int fieldIndex)
-    : INHERITED(position, kField_Kind, owner.fType.fields()[fieldIndex].fName)
+    Field(Position position, std::shared_ptr<Variable> owner, int fieldIndex)
+    : INHERITED(position, kField_Kind, owner->fType->fields()[fieldIndex].fName)
     , fOwner(owner)
     , fFieldIndex(fieldIndex) {}
 
     virtual std::string description() const override {
-        return fOwner.description() + "." + fOwner.fType.fields()[fFieldIndex].fName;
+        return fOwner->description() + "." + fOwner->fType->fields()[fFieldIndex].fName;
     }
 
-    const Variable& fOwner;
+    const std::shared_ptr<Variable> fOwner;
     const int fFieldIndex;
 
     typedef Symbol INHERITED;