MR !2930 (merged) inappropriately commented out the BenchContour benchmarks in
BenchmarkFilters. This was probably done accidently in response to a
comment that suggested that this benchmark was causing a crash. However,
that comment was obsolete. It was introduced in !2196 (merged) when the problem
was identified (2 years ago).
The problem suggested by the comment was soon fixed by MR !2197 (merged). At that time the benchmark was reenabled but the comment lingered on even though it was no longer applicable.
This change restores the benchmark again and deletes the obsolete comment.