Initial error handling code

src/effects/SkBlurImageFilter.cpp

Index: src/effects/SkBlurImageFilter.cpp
diff --git a/src/effects/SkBlurImageFilter.cpp b/src/effects/SkBlurImageFilter.cpp
index 4b2d3b88ffff8ae3ea7838bbd351b0226682419c..21ba3375bb6bfec8c751bc60b34e6b74a27a3753 100644
--- a/src/effects/SkBlurImageFilter.cpp
+++ b/src/effects/SkBlurImageFilter.cpp
@@ -19,6 +19,9 @@ SkBlurImageFilter::SkBlurImageFilter(SkFlattenableReadBuffer& buffer)
   : INHERITED(buffer) {
     fSigma.fWidth = buffer.readScalar();
     fSigma.fHeight = buffer.readScalar();
+    if ((fSigma.fWidth < 0) || (fSigma.fHeight < 0)) {
+        buffer.setError(kInvalidArgument_SkError);

[reed1, 2013/08/21 15:49:24]

should we set fSigma to (0,0) to be "safe" now that we signaled an error?

[sugoi1, 2013/08/21 16:52:36]

I can do that, but it comes back to the original question of who is responsible
for handling errors.

+    }
 }
 
 SkBlurImageFilter::SkBlurImageFilter(SkScalar sigmaX,