started in https://ci.chromium.org/p/chromium/builders/luci.chromium.ci/linux-xenial-rel/338 

and repeats in the next 2 cycles

error is a timeout - https://test-results.appspot.com/data/layout_results/linux-xenial-rel/338/site_per_process_webkit_layout_tests/layout-test-results/results.html

maybe

Roll src/third_party/catapult/ c02f8a850..0e9738361 (1 commit)

https://chromium.googlesource.com/catapult.git/+log/c02f8a85059d..0e97383613e5

$ git log c02f8a850..0e9738361 --date=short --no-merges --format='%ad %ae %s'
2018-05-24 wangxianzhu [Tracing] Remove unused resize_sensor.html and css-element-queries

Created with:
  roll-dep src/third_party/catapult

or

[RLS] Remove RootLayerScrolling references in LocalFrameView.


nothing else looks likely. This is weird.