SkBlurImageFilter returns input when sigma = 0

In the current implementation, a blur filter is always created even in the
case when sigma.fX == 0 && sigma.fY == 0. This CL makes the blur filter
return input in this case.

BUG=568393

Review URL: https://codereview.chromium.org/1518643002

1 files changed, 2 insertions, 1 deletions

diff --git a/gm/imageblur.cpp b/gm/imageblur.cpp
index 575f02c095..22ea408e27 100644
--- a/gm/imageblur.cpp
+++ b/gm/imageblur.cpp
@@ -14,7 +14,8 @@
 
 void imageblurgm_draw(SkScalar fSigmaX, SkScalar fSigmaY, SkCanvas* canvas) {
         SkPaint paint;
-        paint.setImageFilter(SkBlurImageFilter::Create(fSigmaX, fSigmaY))->unref();
+        SkAutoTUnref<SkImageFilter> blur(SkBlurImageFilter::Create(fSigmaX, fSigmaY));
+        paint.setImageFilter(blur);
         canvas->saveLayer(nullptr, &paint);
         const char* str = "The quick brown fox jumped over the lazy dog.";