protect SkPathMeasure against NaN

R=kjlubick@google.com
Bug: skia:7714
Change-Id: I4d260061605404cc7f1b4ee5dd20578cf63c8b2d
Reviewed-on: https://skia-review.googlesource.com/114060
Commit-Queue: Cary Clark <caryclark@skia.org>
Commit-Queue: Cary Clark <caryclark@google.com>
Reviewed-by: Kevin Lubick <kjlubick@google.com>
1 file changed