Switch SkSpecialImage & SkSpecialSurface classes over to smart pointers

src/effects/SkMergeImageFilter.cpp

Index: src/effects/SkMergeImageFilter.cpp
diff --git a/src/effects/SkMergeImageFilter.cpp b/src/effects/SkMergeImageFilter.cpp
index e6761e9960b88c39dfd83233269b0905311080a7..01373b25bfa570cc11bcf601d2b5d9717e2b4285 100755
--- a/src/effects/SkMergeImageFilter.cpp
+++ b/src/effects/SkMergeImageFilter.cpp
@@ -98,7 +98,7 @@ SkSpecialImage* SkMergeImageFilter::onFilterImage(SkSpecialImage* source, const
     SkImageInfo info = SkImageInfo::MakeN32(bounds.width(), bounds.height(),
                                             kPremul_SkAlphaType);
 
-    SkAutoTUnref<SkSpecialSurface> surf(source->newSurface(info));
+    sk_sp<SkSpecialSurface> surf(source->makeSurface(info));
     if (!surf) {
         return nullptr;
     }
@@ -126,7 +126,7 @@ SkSpecialImage* SkMergeImageFilter::onFilterImage(SkSpecialImage* source, const
 
     offset->fX = bounds.left();
     offset->fY = bounds.top();
-    return surf->newImageSnapshot();
+    return surf->makeImageSnapshot().release();
 }
 
 SkFlattenable* SkMergeImageFilter::CreateProc(SkReadBuffer& buffer) {