tunnel down texture-size-constraint to imagefilters

src/effects/SkBlurMaskFilter.cpp

Index: src/effects/SkBlurMaskFilter.cpp
diff --git a/src/effects/SkBlurMaskFilter.cpp b/src/effects/SkBlurMaskFilter.cpp
index d0ff7a228fcf846f1c33e784457e8cb097f827ef..3d32d8d2590de476ff10656e6c91b44a8d84d6fe 100644
--- a/src/effects/SkBlurMaskFilter.cpp
+++ b/src/effects/SkBlurMaskFilter.cpp
@@ -1234,7 +1234,8 @@ bool SkBlurMaskFilterImpl::filterMaskGPU(GrTexture* src,
     // gaussianBlur.  Otherwise, we need to save it for later compositing.
     bool isNormalBlur = (kNormal_SkBlurStyle == fBlurStyle);
     *result = SkGpuBlurUtils::GaussianBlur(context, src, isNormalBlur && canOverwriteSrc,
-                                           clipRect, false, xformedSigma, xformedSigma);
+                                           clipRect, false, xformedSigma, xformedSigma,
+                                           GrTextureProvider::kApprox_SizeConstraint);
     if (nullptr == *result) {
         return false;
     }