This is caused by the hardware upgrade underway on the Windows and Linux GPU bots in the data center in Issue 712469. We've been running at reduced capacity for a few days. I'd hoped this wouldn't be highly visible to Chromium developers, but it has become so.

I'll send out a PSA to chromium-dev. We should be up to full capacity again next Monday. https://chromium-review.googlesource.com/754019 switches to the new hardware configuration (which has more capacity than the old one at this point) and I'll force that through.

The following revision refers to this bug:
  https://chromium.googlesource.com/chromium/src.git/+/c9ed6f61a37399bd175f0011030f3969a3e5f228

commit c9ed6f61a37399bd175f0011030f3969a3e5f228
Author: Kenneth Russell <kbr@chromium.org>
Date: Fri Nov 03 23:26:21 2017

Switch all GeForce GT 610 jobs to Quadro P400.

This switches all of the Windows and Linux bots, and stops triggering
jobs altogether on the GeForce GT 610.

Add suppressions for tests failing/flaking on this configuration.

BUG=712469,  781453 
TBR=jmadill@chromium.org
NOTRY=true

Cq-Include-Trybots: master.tryserver.chromium.android:android_optional_gpu_tests_rel;master.tryserver.chromium.linux:linux_optional_gpu_tests_rel;master.tryserver.chromium.mac:mac_optional_gpu_tests_rel;master.tryserver.chromium.win:win_optional_gpu_tests_rel
Change-Id: Id9471269cff6dce78eb5b8a346beed1d9eacadd5
Reviewed-on: https://chromium-review.googlesource.com/754019
Commit-Queue: Kenneth Russell <kbr@chromium.org>
Reviewed-by: Jamie Madill <jmadill@chromium.org>
Reviewed-by: Kenneth Russell <kbr@chromium.org>
Cr-Commit-Position: refs/heads/master@{#513953}
[modify] https://crrev.com/c9ed6f61a37399bd175f0011030f3969a3e5f228/content/test/gpu/generate_buildbot_json.py
[modify] https://crrev.com/c9ed6f61a37399bd175f0011030f3969a3e5f228/content/test/gpu/gpu_tests/webgl2_conformance_expectations.py
[modify] https://crrev.com/c9ed6f61a37399bd175f0011030f3969a3e5f228/testing/buildbot/chromium.gpu.fyi.json
[modify] https://crrev.com/c9ed6f61a37399bd175f0011030f3969a3e5f228/testing/buildbot/chromium.gpu.json
[modify] https://crrev.com/c9ed6f61a37399bd175f0011030f3969a3e5f228/testing/buildbot/client.v8.fyi.json

At this point there's more capacity on the new Quadro P400s than on the older GeForce GT 610s, and all new jobs are going to the P400s. https://ci.chromium.org/buildbot/tryserver.chromium.win/win7_chromium_rel_ng/?limit=200 has stabilized, and next Monday the upgrade will be complete and all of the capacity will be back online. Closing as Fixed.