change flattenable factory to return sk_sp

src/effects/SkLayerDrawLooper.cpp

Index: src/effects/SkLayerDrawLooper.cpp
diff --git a/src/effects/SkLayerDrawLooper.cpp b/src/effects/SkLayerDrawLooper.cpp
index b3430bb1e4a5e22a6c2d42f36fe3a333f725b3c4..ffcaa43e20c0e0f1cb7e7acaa99a0edd980ca37e 100644
--- a/src/effects/SkLayerDrawLooper.cpp
+++ b/src/effects/SkLayerDrawLooper.cpp
@@ -214,7 +214,7 @@ void SkLayerDrawLooper::flatten(SkWriteBuffer& buffer) const {
     }
 }
 
-SkFlattenable* SkLayerDrawLooper::CreateProc(SkReadBuffer& buffer) {
+sk_sp<SkFlattenable> SkLayerDrawLooper::CreateProc(SkReadBuffer& buffer) {
     int count = buffer.readInt();
 
     Builder builder;
@@ -229,7 +229,7 @@ SkFlattenable* SkLayerDrawLooper::CreateProc(SkReadBuffer& buffer) {
         info.fPostTranslate = buffer.readBool();
         buffer.readPaint(builder.addLayerOnTop(info));
     }
-    return builder.detach().release();
+    return builder.detach();
 }
 
 #ifndef SK_IGNORE_TO_STRING