SkSL performance improvements

src/sksl/ir/SkSLIndexExpression.h

Index: src/sksl/ir/SkSLIndexExpression.h
diff --git a/src/sksl/ir/SkSLIndexExpression.h b/src/sksl/ir/SkSLIndexExpression.h
index 538c656153ad42929bb411ef49fd85d215b6e848..cf993de8354f8108127407eaf34d8450153172f8 100644
--- a/src/sksl/ir/SkSLIndexExpression.h
+++ b/src/sksl/ir/SkSLIndexExpression.h
@@ -16,7 +16,7 @@ namespace SkSL {
 /**
  * Given a type, returns the type that will result from extracting an array value from it.
  */
-static std::shared_ptr<Type> index_type(const Type& type) {
+static const Type& index_type(const Type& type) {
     if (type.kind() == Type::kMatrix_Kind) {
         if (type.componentType() == kFloat_Type) {
             switch (type.columns()) {
@@ -43,7 +43,7 @@ static std::shared_ptr<Type> index_type(const Type& type) {
  */
 struct IndexExpression : public Expression {
     IndexExpression(std::unique_ptr<Expression> base, std::unique_ptr<Expression> index)
-    : INHERITED(base->fPosition, kIndex_Kind, index_type(*base->fType))
+    : INHERITED(base->fPosition, kIndex_Kind, index_type(base->fType))
     , fBase(std::move(base))
     , fIndex(std::move(index)) {
         ASSERT(fIndex->fType == kInt_Type);