SkBlurImageFilter returns input when sigma = 0

include/effects/SkBlurImageFilter.h

Index: include/effects/SkBlurImageFilter.h
diff --git a/include/effects/SkBlurImageFilter.h b/include/effects/SkBlurImageFilter.h
index 7f62634a9eb9b6d58bcc2c72c85d5dae2c2bc527..32e010cbcd245efba2aefcbf44fae2a67323378c 100644
--- a/include/effects/SkBlurImageFilter.h
+++ b/include/effects/SkBlurImageFilter.h
@@ -15,6 +15,8 @@ class SK_API SkBlurImageFilter : public SkImageFilter {
 public:
     static SkImageFilter* Create(SkScalar sigmaX, SkScalar sigmaY, SkImageFilter* input = NULL,
                                  const CropRect* cropRect = NULL) {
+        if (0.0f == sigmaX && 0.0f == sigmaY && NULL == cropRect)

[Stephen White, 2015/12/10 16:05:40]

Skia coding style requires braces on all statement blocks.

Also, prefer 0 for SkScalar zero, and nullptr for NULL.

[xidachen, 2015/12/10 16:17:44]

Done.

+            return input;
         return new SkBlurImageFilter(sigmaX, sigmaY, input, cropRect);
     }