change flattenable factory to return sk_sp

src/effects/SkCornerPathEffect.cpp

Index: src/effects/SkCornerPathEffect.cpp
diff --git a/src/effects/SkCornerPathEffect.cpp b/src/effects/SkCornerPathEffect.cpp
index c38889c60828a957e597fff5975b70349a19897f..909ef31478a7e0db91f326edae30c57ada198d99 100644
--- a/src/effects/SkCornerPathEffect.cpp
+++ b/src/effects/SkCornerPathEffect.cpp
@@ -138,8 +138,8 @@ DONE:
     return true;
 }
 
-SkFlattenable* SkCornerPathEffect::CreateProc(SkReadBuffer& buffer) {
-    return SkCornerPathEffect::Make(buffer.readScalar()).release();
+sk_sp<SkFlattenable> SkCornerPathEffect::CreateProc(SkReadBuffer& buffer) {
+    return SkCornerPathEffect::Make(buffer.readScalar());
 }
 
 void SkCornerPathEffect::flatten(SkWriteBuffer& buffer) const {