Fix DistanceFieldPathRenderer assert.

If there's a reflection in the matrix, the scales
could be negative.

BUG=chromium:682918

Change-Id: Ifde42c3bc8b1f2938009b47d3a8380cf871448e9
Reviewed-on: https://skia-review.googlesource.com/8541
Reviewed-by: Jim Van Verth <jvanverth@google.com>
Commit-Queue: Jim Van Verth <jvanverth@google.com>
1 file changed