Update SkMergeImageFilter to sk_sp

bench/ImageFilterDAGBench.cpp

Index: bench/ImageFilterDAGBench.cpp
diff --git a/bench/ImageFilterDAGBench.cpp b/bench/ImageFilterDAGBench.cpp
index d66d287e1817f217f75a652607c7b07dfe3bdb07..5fdf95b06d37ee1e387a4b084f7c65b86743cac7 100644
--- a/bench/ImageFilterDAGBench.cpp
+++ b/bench/ImageFilterDAGBench.cpp
@@ -11,12 +11,10 @@
 #include "SkCanvas.h"
 #include "SkMergeImageFilter.h"
 
-enum { kNumInputs = 5 };
 
 // Exercise a blur filter connected to 5 inputs of the same merge filter.
 // This bench shows an improvement in performance once cacheing of re-used
 // nodes is implemented, since the DAG is no longer flattened to a tree.
-
 class ImageFilterDAGBench : public Benchmark {
 public:
     ImageFilterDAGBench() {}
@@ -27,21 +25,23 @@ protected:
     }
 
     void onDraw(int loops, SkCanvas* canvas) override {
+        const SkRect rect = SkRect::Make(SkIRect::MakeWH(400, 400));
+
         for (int j = 0; j < loops; j++) {
-            SkAutoTUnref<SkImageFilter> blur(SkBlurImageFilter::Create(20.0f, 20.0f));
-            SkImageFilter* inputs[kNumInputs];
+            sk_sp<SkImageFilter> blur(SkBlurImageFilter::Create(20.0f, 20.0f));
+            sk_sp<SkImageFilter> inputs[kNumInputs];
             for (int i = 0; i < kNumInputs; ++i) {
-                inputs[i] = blur.get();
+                inputs[i] = blur;
             }
-            SkAutoTUnref<SkImageFilter> merge(SkMergeImageFilter::Create(inputs, kNumInputs));
             SkPaint paint;
-            paint.setImageFilter(merge);
-            SkRect rect = SkRect::Make(SkIRect::MakeWH(400, 400));
+            paint.setImageFilter(SkMergeImageFilter::Make(inputs, kNumInputs));
             canvas->drawRect(rect, paint);
         }
     }
 
 private:
+    static const int kNumInputs = 5;
+
     typedef Benchmark INHERITED;
 };