Update SkMorphology ImageFilters to sk_sp

TBR=reed@google.com

GOLD_TRYBOT_URL= https://gold.skia.org/search2?unt=true&query=source_type%3Dgm&master=false&issue=1860573002

Review URL: https://codereview.chromium.org/1860573002
diff --git a/samplecode/SampleLayers.cpp b/samplecode/SampleLayers.cpp
index 8c2724c..194f0a7 100644
--- a/samplecode/SampleLayers.cpp
+++ b/samplecode/SampleLayers.cpp
@@ -245,13 +245,13 @@
     SkPoint fCenter;
     SkScalar fAngle;
     sk_sp<SkImage> fImage;
-    SkAutoTUnref<SkImageFilter> fFilter;
+    sk_sp<SkImageFilter> fFilter;
 public:
     BackdropView() {
         fCenter.set(200, 150);
         fAngle = 0;
         fImage = GetResourceAsImage("mandrill_512.png");
-        fFilter.reset(SkDilateImageFilter::Create(8, 8));
+        fFilter = SkDilateImageFilter::Make(8, 8, nullptr);
     }
 
 protected:
@@ -281,7 +281,7 @@
 
         SkPaint paint;
         paint.setAlpha(0xCC);
-        canvas->saveLayer({ &bounds, &paint, fFilter, 0 });
+        canvas->saveLayer({ &bounds, &paint, fFilter.get(), 0 });
 
         canvas->restore();
     }