hide setImageFilter(ptr)

BUG=skia:

GOLD_TRYBOT_URL= https://gold.skia.org/search?issue=4184

Change-Id: Iad792cfdf54087ad4c424fd268559c162a9a5f5c
Reviewed-on: https://skia-review.googlesource.com/4184
Reviewed-by: Florin Malita <fmalita@chromium.org>
Commit-Queue: Mike Reed <reed@google.com>
diff --git a/tests/PDFPrimitivesTest.cpp b/tests/PDFPrimitivesTest.cpp
index 2d9468e..81b33ba 100644
--- a/tests/PDFPrimitivesTest.cpp
+++ b/tests/PDFPrimitivesTest.cpp
@@ -400,7 +400,7 @@
     // Filter just created; should be unvisited.
     REPORTER_ASSERT(reporter, !filter->visited());
     SkPaint paint;
-    paint.setImageFilter(filter.get());
+    paint.setImageFilter(filter);
     canvas->drawRect(SkRect::MakeWH(100, 100), paint);
     doc->close();