change flattenable factory to return sk_sp

src/effects/SkLayerRasterizer.cpp

Index: src/effects/SkLayerRasterizer.cpp
diff --git a/src/effects/SkLayerRasterizer.cpp b/src/effects/SkLayerRasterizer.cpp
index a51613a162c78155464bf3f6d048c7d28327ccc1..91502b7e8446d8ebe5434db7d573a4a0221ac9cb 100644
--- a/src/effects/SkLayerRasterizer.cpp
+++ b/src/effects/SkLayerRasterizer.cpp
@@ -144,8 +144,8 @@ bool SkLayerRasterizer::onRasterize(const SkPath& path, const SkMatrix& matrix,
     return true;
 }
 
-SkFlattenable* SkLayerRasterizer::CreateProc(SkReadBuffer& buffer) {
-    return new SkLayerRasterizer(ReadLayers(buffer));
+sk_sp<SkFlattenable> SkLayerRasterizer::CreateProc(SkReadBuffer& buffer) {
+    return sk_sp<SkFlattenable>(new SkLayerRasterizer(ReadLayers(buffer)));
 }
 
 SkDeque* SkLayerRasterizer::ReadLayers(SkReadBuffer& buffer) {