change flattenable factory to return sk_sp

src/effects/SkDisplacementMapEffect.cpp

Index: src/effects/SkDisplacementMapEffect.cpp
diff --git a/src/effects/SkDisplacementMapEffect.cpp b/src/effects/SkDisplacementMapEffect.cpp
index d054e58e51f2a416730fd3bafb09d0c0e1a2db25..447a20bcb267de834a121c0126c690c7ecea7c28 100644
--- a/src/effects/SkDisplacementMapEffect.cpp
+++ b/src/effects/SkDisplacementMapEffect.cpp
@@ -195,13 +195,13 @@ SkDisplacementMapEffect::SkDisplacementMapEffect(ChannelSelectorType xChannelSel
 SkDisplacementMapEffect::~SkDisplacementMapEffect() {
 }
 
-SkFlattenable* SkDisplacementMapEffect::CreateProc(SkReadBuffer& buffer) {
+sk_sp<SkFlattenable> SkDisplacementMapEffect::CreateProc(SkReadBuffer& buffer) {
     SK_IMAGEFILTER_UNFLATTEN_COMMON(common, 2);
     ChannelSelectorType xsel = (ChannelSelectorType)buffer.readInt();
     ChannelSelectorType ysel = (ChannelSelectorType)buffer.readInt();
     SkScalar scale = buffer.readScalar();
-    return Create(xsel, ysel, scale,
-                  common.getInput(0).get(), common.getInput(1).get(), &common.cropRect());
+    return sk_sp<SkFlattenable>(Create(xsel, ysel, scale, common.getInput(0).get(),
+                                       common.getInput(1).get(), &common.cropRect()));
 }
 
 void SkDisplacementMapEffect::flatten(SkWriteBuffer& buffer) const {