Implement crop rect for SkImageFilter

src/effects/SkBlurMaskFilter.cpp

Index: src/effects/SkBlurMaskFilter.cpp
diff --git a/src/effects/SkBlurMaskFilter.cpp b/src/effects/SkBlurMaskFilter.cpp
index 64c437d80151392e7f8a6b5365c394332f58511e..f1fee065f8f41ef7297c15d04b98aa2350b066a2 100644
--- a/src/effects/SkBlurMaskFilter.cpp
+++ b/src/effects/SkBlurMaskFilter.cpp
@@ -412,7 +412,7 @@ bool SkBlurMaskFilterImpl::filterMaskGPU(GrTexture* src,
     // gaussianBlur.  Otherwise, we need to save it for later compositing.
     bool isNormalBlur = (SkBlurMaskFilter::kNormal_BlurStyle == fBlurStyle);
     *result = SkGpuBlurUtils::GaussianBlur(context, src, isNormalBlur && canOverwriteSrc,
-                                           clipRect, sigma, sigma);
+                                           clipRect, false, sigma, sigma);
     if (NULL == *result) {
         return false;
     }