GN: add sksl

BUG=skia:
GOLD_TRYBOT_URL= https://gold.skia.org/search?issue=2296803002

Review-Url: https://codereview.chromium.org/2296803002
diff --git a/BUILD.gn b/BUILD.gn
index 67347ea..7f16f7b 100644
--- a/BUILD.gn
+++ b/BUILD.gn
@@ -68,6 +68,7 @@
     "src/pdf",
     "src/ports",
     "src/sfnt",
+    "src/sksl",
     "src/utils",
     "src/utils/win",
     "third_party/etc1",
@@ -134,6 +135,15 @@
                        "scope",
                        [ "gyp/pdf.gypi" ])
 
+sksl_gypi = exec_script("gn/gypi_to_gn.py",
+                        [
+                          rebase_path("gyp/sksl.gypi"),
+                          "--replace=<(skia_include_path)=include",
+                          "--replace=<(skia_src_path)=src",
+                        ],
+                        "scope",
+                        [ "gyp/sksl.gypi" ])
+
 utils_gypi = exec_script("gn/gypi_to_gn.py",
                          [
                            rebase_path("gyp/utils.gypi"),
@@ -410,6 +420,7 @@
   sources += core_gypi.sources
   sources += effects_gypi.sources
   sources += gpu_gypi.skgpu_sources
+  sources += sksl_gypi.sources
   sources += utils_gypi.sources
   sources += [
     "src/android/SkBitmapRegionCodec.cpp",
@@ -688,8 +699,6 @@
     public_include_dirs = [ "tests" ]
     sources = tests_sources - [
                 rebase_path("tests/PathOpsSkpClipTest.cpp"),  # alternate main
-                rebase_path("tests/SkSLErrorTest.cpp"),  # TODO: make work
-                rebase_path("tests/SkSLGLSLTest.cpp"),  # TODO: make work
                 rebase_path("tests/SkpSkGrTest.cpp"),  # doesn't compile
                 rebase_path("tests/skia_test.cpp"),  # alternate main
               ]