Make degenerate kernel in fill_in_2D_gaussian_kernel sum to 1

Bug: 836113
Change-Id: I1b2ed1d67648163571df6c497365d2a293b3b589
Reviewed-on: https://skia-review.googlesource.com/126020
Reviewed-by: Herb Derby <herb@google.com>
Commit-Queue: Robert Phillips <robertphillips@google.com>
1 file changed