SkBlurImageFilter returns input when sigma = 0

gm/imageblurtiled.cpp

 /*
  * Copyright 2014 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 "SkRandom.h"
@@ skipping 13 matching lines @@
     virtual SkString onShortName() {
         return SkString("imageblurtiled");
     }
 
     virtual SkISize onISize() {
         return SkISize::Make(WIDTH, HEIGHT);
     }
 
     virtual void onDraw(SkCanvas* canvas) {
         SkPaint paint;
-        paint.setImageFilter(SkBlurImageFilter::Create(fSigmaX, fSigmaY))->unref();
+        SkAutoTUnref<SkImageFilter> blur(SkBlurImageFilter::Create(fSigmaX, fSigmaY));
+        paint.setImageFilter(blur);
         const SkScalar tile_size = SkIntToScalar(128);
         SkRect bounds;
         if (!canvas->getClipBounds(&bounds)) {
             bounds.setEmpty();
         }
         for (SkScalar y = bounds.top(); y < bounds.bottom(); y += tile_size) {
             for (SkScalar x = bounds.left(); x < bounds.right(); x += tile_size) {
                 canvas->save();
                 canvas->clipRect(SkRect::MakeXYWH(x, y, tile_size, tile_size));
                 canvas->saveLayer(nullptr, &paint);
@@ skipping 25 matching lines @@
 
     typedef GM INHERITED;
 };
 
 //////////////////////////////////////////////////////////////////////////////
 
 static GM* MyFactory1(void*) { return new ImageBlurTiledGM(3.0f, 3.0f); }
 static GMRegistry reg1(MyFactory1);
 
 }