What does this entail exactly? Removing anything x86-generic-* from the build repo?

That sounds right. Don, can you comment on that?

Yep.

This waterfall:

https://build.chromium.org/p/chromiumos.chromium/waterfall

Looks like this is the only build config to remove:

'x86-generic-tot-chromium-pfq-informational'

The following revision refers to this bug:
  https://chromium.googlesource.com/chromium/tools/build/+/d8c3c55f96a27223d94c106fc7c94d11af717b6d

commit d8c3c55f96a27223d94c106fc7c94d11af717b6d
Author: Jeff Carpenter <jeffcarp@chromium.org>
Date: Tue Aug 01 20:31:45 2017

Remove 32-bit builders from waterfall

Chrome OS would like all 32-bit Chrome PFQ informational builders from the chromiumos.chromium waterfall.

Bug:  750905 
Change-Id: I83596ce42579807ad2a7e5ac44fc69b8f4009770
Reviewed-on: https://chromium-review.googlesource.com/595232
Commit-Queue: Don Garrett <dgarrett@chromium.org>
Reviewed-by: Don Garrett <dgarrett@chromium.org>
Reviewed-by: Aaron Gable <agable@chromium.org>
Reviewed-by: Paul Hobbs <phobbs@google.com>

[modify] https://crrev.com/d8c3c55f96a27223d94c106fc7c94d11af717b6d/masters/master.chromiumos/templates/announce.html
[modify] https://crrev.com/d8c3c55f96a27223d94c106fc7c94d11af717b6d/masters/master.chromiumos.chromium/slaves.cfg
[modify] https://crrev.com/d8c3c55f96a27223d94c106fc7c94d11af717b6d/masters/master.chromiumos.chromium/master_chromium_cfg.py

Builders will be removed next time the master restarts. Removing from trooper queue.