Looks like the right link is https://test-results.appspot.com/revision_range?start=465287&end=465295

Did something change recently on the SoM side?

I don't know of any recent changes to regression range links on Sheriff-o-Matic's end but maybe. Either way, this should be simple to fix I think. 

Huh, actually I'm not sure what's happening here. The links for me seem to work. And the URL in the code is hardcoded as: 

'https://test-results.appspot.com/revision_range?start=' +
          `${start}&end=${end}`

So I'm not sure where the /data/ in the URL that broke the link came from. 

Oh, okay, nevermind. I see, this is actually on the test-results side. 

That was probably my fault. I was migrating all JSON-endpoints to /data/ prefix and originally migrated /revision_range as well. Later, however, I've realized that this was not a JSON endpoint and reverted the change. Looks like I forgot to revert updates made to other places: https://cs.chromium.org/search/?q=/data/revision_range+package:%5Echromium$&type=cs.

I'll prepare a CL.

CL: https://chromium-review.googlesource.com/c/481302/

The following revision refers to this bug:
  https://chromium.googlesource.com/infra/infra/+/d1036ea398b5cc8651ba9f54305eda4fa0e46ef6

commit d1036ea398b5cc8651ba9f54305eda4fa0e46ef6
Author: Sergiy Byelozyorov <sergiyb@chromium.org>
Date: Wed Apr 19 12:48:29 2017

Remove /data/ from revision range URLs on Flakiness Dashboard

As part of moving JSON endpoints on Test Results Server into /data/ subpath,
I've also moved /revision_range to /data/revision_range. Later I have realized
that this is not a JSON endpoint and therefore moved it back to /revision_range.
However, I forgot to also revert changes to the URLs in the Flakiness Dashboard
UI, which is what this CL fixes.

Bug:  712805 
Change-Id: Id3f02b1b57980b83ca70c246b18d7c75c296cb07
Reviewed-on: https://chromium-review.googlesource.com/481302
Reviewed-by: Andrii Shyshkalov <tandrii@chromium.org>
Commit-Queue: Sergiy Byelozyorov <sergiyb@chromium.org>

[modify] https://crrev.com/d1036ea398b5cc8651ba9f54305eda4fa0e46ef6/go/src/infra/appengine/test-results/frontend/static/dashboards/js/ui.js
[modify] https://crrev.com/d1036ea398b5cc8651ba9f54305eda4fa0e46ef6/go/src/infra/appengine/test-results/frontend/static/dashboards/js/ui_unittests.js
[modify] https://crrev.com/d1036ea398b5cc8651ba9f54305eda4fa0e46ef6/go/src/infra/appengine/test-results/frontend/static/dashboards/js/flakiness_dashboard_unittests.js

Deployed revision c76b51ab8 to the test-results app.