added sksl to Skia BUILD.gn

skia/BUILD.gn

Index: skia/BUILD.gn
diff --git a/skia/BUILD.gn b/skia/BUILD.gn
index 453bf59ca3cf2327caa8d5ad3d8cface8c15d4f3..52f9fc831586c3baf3a56a4b26ae91390dd407a2 100644
--- a/skia/BUILD.gn
+++ b/skia/BUILD.gn
@@ -68,6 +68,7 @@ config("skia_config") {
     include_dirs += [
       "//third_party/skia/include/gpu",
       "//third_party/skia/src/gpu",
+      "//third_party/skia/src/sksl",
     ]
     defines += [ "SK_SUPPORT_GPU=1" ]
   } else {
@@ -283,6 +284,7 @@ component("skia") {
   if (skia_support_gpu) {
     sources += skia_gpu_sources
     sources += skia_null_gpu_sources
+    sources += skia_sksl_sources
   }
 
   # Remove unused util files include in utils.gypi