What is the replacement for this feature? / How will this work in the future if someone disables a benchmark on all platforms?

Is the replacement what is described in  issue 911828 ? "some sort of temporary black list"?

Remove that benchmark completely?

The following revision refers to this bug:
  https://chromium.googlesource.com/chromium/src.git/+/c216657a43a7cfb615ea28d026c39f103d285f3a

commit c216657a43a7cfb615ea28d026c39f103d285f3a
Author: Ned Nguyen <nednguyen@google.com>
Date: Wed Dec 05 03:53:24 2018

Refactor perf_data_generator and remove not_scheduled field in BenchmarkMetadata

These clean up are preparation for fixing error handling of unscheduled benchmarks (
 crbug.com/911828 

This is a pure refactoring CL and should have no effects

Bug:  875232 
Change-Id: I7e0d7c235996833ab00ee8ed0f49ebbc2bca65a2
Reviewed-on: https://chromium-review.googlesource.com/c/1362286
Commit-Queue: Ned Nguyen <nednguyen@google.com>
Reviewed-by: Caleb Rouleau <crouleau@chromium.org>
Cr-Commit-Position: refs/heads/master@{#613856}
[modify] https://crrev.com/c216657a43a7cfb615ea28d026c39f103d285f3a/tools/perf/core/perf_data_generator.py