In the PaygenTestDev stage of this build:

https://uberchromegw.corp.google.com/i/chromeos/builders/nyan_kitty-release/builds/1199

When downloading the crashinfo logs from here:
https://pantheon.corp.google.com/storage/browser/chromeos-autotest-results/123705079-chromeos-test/chromeos4-row13-rack8-host8/

What appear to be render process logs have the message:

FATAL:gpu_process_transport_factory.cc(374)] Unable to create a UI graphics context, and cannot use software compositing on ChromeOS.

And the browser has the log:

ERROR:browser_gpu_channel_host_factory.cc(103)] Failed to launch GPU process.

It may be possible that this is a red herring, but more likely it is the cause of this failure: issue 734074, which is only occuring on nyan boards.

cc'ing anyone who made gpu related changes in this range where issue 734074 was introduced:
https://chromium.googlesource.com/chromium/src/+log/61.0.3131.0..61.0.3132.0?pretty=fuller&n=10000

Any help debugging this will be much appreciated!