change flattenable factory to return sk_sp

src/effects/SkTestImageFilters.cpp

Index: src/effects/SkTestImageFilters.cpp
diff --git a/src/effects/SkTestImageFilters.cpp b/src/effects/SkTestImageFilters.cpp
index a77f5190ffde0ed4d13db5a6ee737417b60dd7cb..e9ec7c19ceb6cd80f1445835daf95c1fed08f7c8 100755
--- a/src/effects/SkTestImageFilters.cpp
+++ b/src/effects/SkTestImageFilters.cpp
@@ -75,9 +75,9 @@ bool SkDownSampleImageFilter::onFilterImageDeprecated(Proxy* proxy, const SkBitm
     return true;
 }
 
-SkFlattenable* SkDownSampleImageFilter::CreateProc(SkReadBuffer& buffer) {
+sk_sp<SkFlattenable> SkDownSampleImageFilter::CreateProc(SkReadBuffer& buffer) {
     SK_IMAGEFILTER_UNFLATTEN_COMMON(common, 1);
-    return Create(buffer.readScalar(), common.getInput(0).get());
+    return sk_sp<SkFlattenable>(Create(buffer.readScalar(), common.getInput(0).get()));
 }
 
 void SkDownSampleImageFilter::flatten(SkWriteBuffer& buffer) const {