SkBlurImageFilter returns input when sigma = 0

gm/imagefilters.cpp

 /*
  * Copyright 2015 Google Inc.
  *
  * Use of this source code is governed by a BSD-style license that can be
  * found in the LICENSE file.
  */
 
 #include "gm.h"
 #include "SkBlurImageFilter.h"
 #include "SkColorMatrixFilter.h"
@@ skipping 69 matching lines @@
 //
 // Expect the two to draw the same (modulo the extra border of pixels when the clip is larger)
 //
 DEF_SIMPLE_GM(fast_slow_blurimagefilter, canvas, 620, 260) {
     SkAutoTUnref<SkImage> image(make_image(canvas));
     const SkRect r = SkRect::MakeIWH(image->width(), image->height());
 
     canvas->translate(10, 10);
     for (SkScalar sigma = 8; sigma <= 128; sigma *= 2) {
         SkPaint paint;
-        paint.setImageFilter(SkBlurImageFilter::Create(sigma, sigma))->unref();
+        SkAutoTUnref<SkImageFilter> blur(SkBlurImageFilter::Create(sigma, sigma));
+        paint.setImageFilter(blur.get());
 
         canvas->save();
         // we outset the clip by 1, to fall out of the fast-case in drawImage
         // i.e. the clip is larger than the image
         for (SkScalar outset = 0; outset <= 1; ++outset) {
             canvas->save();
             canvas->clipRect(r.makeOutset(outset, outset));
             canvas->drawImage(image, 0, 0, &paint);
             canvas->restore();
             canvas->translate(0, r.height() + 20);
         }
         canvas->restore();
         canvas->translate(r.width() + 20, 0);
     }
 }