[skottie] Layer clip support

TBR=

Change-Id: Ibf65efc69031f8f6e19f4f28cccab29c357e704d
Reviewed-on: https://skia-review.googlesource.com/101540
Reviewed-by: Florin Malita <fmalita@chromium.org>
Commit-Queue: Florin Malita <fmalita@chromium.org>
diff --git a/BUILD.gn b/BUILD.gn
index 9eb4022..5514093 100644
--- a/BUILD.gn
+++ b/BUILD.gn
@@ -1400,6 +1400,7 @@
       "experimental/sksg/SkSGPaintNode.cpp",
       "experimental/sksg/SkSGRenderNode.cpp",
       "experimental/sksg/SkSGScene.cpp",
+      "experimental/sksg/effects/SkSGClipEffect.cpp",
       "experimental/sksg/effects/SkSGMaskEffect.cpp",
       "experimental/sksg/effects/SkSGOpacityEffect.cpp",
       "experimental/sksg/effects/SkSGTransform.cpp",