[skotty,sksg] Initial trim path effect

TBR=
Change-Id: I5b612c5aade23f727a3622daeff2534f68e6b66a
Reviewed-on: https://skia-review.googlesource.com/91404
Reviewed-by: Florin Malita <fmalita@chromium.org>
Commit-Queue: Florin Malita <fmalita@chromium.org>
diff --git a/BUILD.gn b/BUILD.gn
index fe58f50..cc1e844 100644
--- a/BUILD.gn
+++ b/BUILD.gn
@@ -1387,6 +1387,7 @@
       "experimental/sksg/geometry/SkSGMerge.cpp",
       "experimental/sksg/geometry/SkSGPath.cpp",
       "experimental/sksg/geometry/SkSGRect.cpp",
+      "experimental/sksg/geometry/SkSGTrimEffect.cpp",
       "experimental/sksg/paint/SkSGColor.cpp",
     ]
     deps = [