UserAgent: Mozilla/5.0 (X11; Ubuntu; Linux x86_64; rv:57.0) Gecko/20100101 Firefox/57.0

Steps to reproduce the problem:
1. build latest code of filter_fuzz_stub with following gn flags:
is_debug = true
(ninja -C buildir skia:filter_fuzz_stub)
2. Run filter_fuzz_stub with attached file:
./filter_fuzz_stub  tileMode.fil
[0108/175430.566310:INFO:SkBlurImageFilter.cpp(120)] ../../third_party/skia/src/core/SkBlurImageFilter.cpp:120: fatal error: "assert(tileMode <= SkBlurImageFilter::kMax_TileMode)"

Aborted

What is the expected behavior?

What went wrong?
fatal error: "assert(tileMode <= SkBlurImageFilter::kMax_TileMode)"

Did this work before? N/A 

Chrome version: 65.0.3307.0  Channel: n/a
OS Version: 16.04
Flash Version: