Update internal testing ImageFilters to sk_sp

GOLD_TRYBOT_URL= https://gold.skia.org/search2?unt=true&query=source_type%3Dgm&master=false&issue=1854023003

Review URL: https://codereview.chromium.org/1854023003
diff --git a/tests/PDFPrimitivesTest.cpp b/tests/PDFPrimitivesTest.cpp
index f4c29b3..ac3b28b 100644
--- a/tests/PDFPrimitivesTest.cpp
+++ b/tests/PDFPrimitivesTest.cpp
@@ -364,8 +364,15 @@
 
 class DummyImageFilter : public SkImageFilter {
 public:
-    DummyImageFilter(bool visited = false) : SkImageFilter(0, nullptr), fVisited(visited) {}
-    ~DummyImageFilter() override {}
+    static sk_sp<DummyImageFilter> Make(bool visited = false) {
+        return sk_sp<DummyImageFilter>(new DummyImageFilter(visited));
+    }
+
+    SK_TO_STRING_OVERRIDE()
+    SK_DECLARE_PUBLIC_FLATTENABLE_DESERIALIZATION_PROCS(DummyImageFilter)
+    bool visited() const { return fVisited; }
+
+protected:
     bool onFilterImageDeprecated(Proxy*, const SkBitmap& src, const Context&,
                                  SkBitmap* result, SkIPoint* offset) const override {
         fVisited = true;
@@ -373,18 +380,19 @@
         *result = src;
         return true;
     }
-    SK_TO_STRING_OVERRIDE()
-    SK_DECLARE_PUBLIC_FLATTENABLE_DESERIALIZATION_PROCS(DummyImageFilter)
-    bool visited() const { return fVisited; }
 
 private:
+    DummyImageFilter(bool visited) : INHERITED(nullptr, 0, nullptr), fVisited(visited) {}
+
     mutable bool fVisited;
+
+    typedef SkImageFilter INHERITED;
 };
 
 sk_sp<SkFlattenable> DummyImageFilter::CreateProc(SkReadBuffer& buffer) {
     SK_IMAGEFILTER_UNFLATTEN_COMMON(common, 0);
     bool visited = buffer.readBool();
-    return sk_make_sp<DummyImageFilter>(visited);
+    return DummyImageFilter::Make(visited);
 }
 
 #ifndef SK_IGNORE_TO_STRING
@@ -403,7 +411,7 @@
     sk_sp<SkDocument> doc(SkDocument::CreatePDF(&stream));
     SkCanvas* canvas = doc->beginPage(100.0f, 100.0f);
 
-    sk_sp<DummyImageFilter> filter(new DummyImageFilter());
+    sk_sp<DummyImageFilter> filter(DummyImageFilter::Make());
 
     // Filter just created; should be unvisited.
     REPORTER_ASSERT(reporter, !filter->visited());