[skif] Update MatrixConvolution to use FilterResult

Change-Id: Ia6480a61a84eccaa6987498278fe1daa5527dd80
Reviewed-on: https://skia-review.googlesource.com/c/skia/+/724960
Reviewed-by: Robert Phillips <robertphillips@google.com>
Reviewed-by: Brian Osman <brianosman@google.com>
Commit-Queue: Michael Ludwig <michaelludwig@google.com>
7 files changed