Update DownSampleImageFilter to sk_sp

include/effects/SkTestImageFilters.h

Index: include/effects/SkTestImageFilters.h
diff --git a/include/effects/SkTestImageFilters.h b/include/effects/SkTestImageFilters.h
index 943bb533562d03cbbfb2cee9151e69ef1a73985a..0f89759c1c8dd141d059945b5097046f52c45230 100644
--- a/include/effects/SkTestImageFilters.h
+++ b/include/effects/SkTestImageFilters.h
@@ -14,20 +14,26 @@
 // Fun mode that scales down (only) and then scales back up to look pixelated
 class SK_API SkDownSampleImageFilter : public SkImageFilter {
 public:
-    static SkImageFilter* Create(SkScalar scale, SkImageFilter* input = NULL) {
+    static sk_sp<SkImageFilter> Make(SkScalar scale, sk_sp<SkImageFilter> input) {
         if (!SkScalarIsFinite(scale)) {
-            return NULL;
+            return nullptr;
         }
         // we don't support scale in this range
         if (scale > SK_Scalar1 || scale <= 0) {
-            return NULL;
+            return nullptr;
         }
-        return new SkDownSampleImageFilter(scale, input);
+        return sk_sp<SkImageFilter>(new SkDownSampleImageFilter(scale, std::move(input)));
     }
 
     SK_TO_STRING_OVERRIDE()
     SK_DECLARE_PUBLIC_FLATTENABLE_DESERIALIZATION_PROCS(SkDownSampleImageFilter)
 
+#ifdef SK_SUPPORT_LEGACY_IMAGEFILTER_PTR
+    static SkImageFilter* Create(SkScalar scale, SkImageFilter* input = nullptr) {
+        return Make(scale, sk_ref_sp<SkImageFilter>(input)).release();
+    }
+#endif
+
 protected:
     void flatten(SkWriteBuffer&) const override;
 
@@ -35,8 +41,8 @@ protected:
                                         SkIPoint* offset) const override;
 
 private:
-    SkDownSampleImageFilter(SkScalar scale, SkImageFilter* input)
-        : INHERITED(1, &input), fScale(scale) {}
+    SkDownSampleImageFilter(SkScalar scale, sk_sp<SkImageFilter> input)
+        : INHERITED(&input, 1, nullptr), fScale(scale) {}
 
     SkScalar fScale;