skslc can now be compiled with no Skia dependencies, in preparation for its eventual

This reverts commit 9bd301d640ff63c280b202c7dd00bc00a3315ff4.

Bug: skia:
Change-Id: I5ad3f77ef33aa5ce2fd27fe383c9339c571663a1
Reviewed-on: https://skia-review.googlesource.com/10964
Reviewed-by: Ethan Nicholas <ethannicholas@google.com>
Commit-Queue: Ethan Nicholas <ethannicholas@google.com>
diff --git a/gn/sksl.gni b/gn/sksl.gni
index 748466f..a1cab82 100644
--- a/gn/sksl.gni
+++ b/gn/sksl.gni
@@ -13,6 +13,7 @@
   "$_src/sksl/SkSLParser.cpp",
   "$_src/sksl/SkSLGLSLCodeGenerator.cpp",
   "$_src/sksl/SkSLSPIRVCodeGenerator.cpp",
+  "$_src/sksl/SkSLString.cpp",
   "$_src/sksl/SkSLUtil.cpp",
   "$_src/sksl/lex.layout.cpp",
   "$_src/sksl/ir/SkSLSymbolTable.cpp",