It seems most pronounced with rendering.desktop/yahoo_news*. Output complains about missing resources:

(WARNING) 2018-11-09 09:36:30,843 inspector_log._OnMessage:26  DevTools console [network]: Failed to load resource: the server responded with a status of 404 () https://s.yimg.com/uu/api/res/1.2/jSzZgE8awpnl1iK5ewhp_Q--~B/Zmk9c3RyaW07aD0zODY7cHlvZmY9MDtxPTgwO3c9NDQwO3NtPTE7YXBwaWQ9eXRhY2h5b24-/http://media.zenfs.com/en-US/homerun/the_huffington_post_584/62b07dba096985d3502d58f4d58e1374.cf.webp
(WARNING) 2018-11-09 09:36:30,843 inspector_log._OnMessage:26  DevTools console [network]: Failed to load resource: the server responded with a status of 404 () https://s.yimg.com/rz/d/yahoo_news_en-US_s_f_pw_351x40_news_2x.png
(WARNING) 2018-11-09 09:36:32,306 inspector_log._OnMessage:26  DevTools console [network]: Failed to load resource: the server responded with a status of 400 (Bad Request) https://guce.yahoo.com/v1/consentRecord?consentTypes=iab&apid=CM7f29b480-7eff-11e8-b676-777676767676
(WARNING) 2018-11-09 09:36:32,306 inspector_log._OnMessage:26  DevTools console [network]: Failed to load resource: the server responded with a status of 404 () https://s.yimg.com/uu/api/res/1.2/jSzZgE8awpnl1iK5ewhp_Q--~B/Zmk9c3RyaW07aD0zODY7cHlvZmY9MDtxPTgwO3c9NDQwO3NtPTE7YXBwaWQ9eXRhY2h5b24-/http://media.zenfs.com/en-US/homerun/the_huffington_post_584/62b07dba096985d3502d58f4d58e1374.cf.webp
(WARNING) 2018-11-09 09:36:32,307 inspector_log._OnMessage:26  DevTools console [network]: Failed to load resource: the server responded with a status of 404 () https://s.yimg.com/uu/api/res/1.2/jSzZgE8awpnl1iK5ewhp_Q--~B/Zmk9c3RyaW07aD0zODY7cHlvZmY9MDtxPTgwO3c9NDQwO3NtPTE7YXBwaWQ9eXRhY2h5b24-/http://media.zenfs.com/en-US/homerun/the_huffington_post_584/62b07dba096985d3502d58f4d58e1374.cf.webp
(WARNING) 2018-11-09 09:36:32,334 inspector_log._OnMessage:26  DevTools console [network]: Failed to load resource: the server responded with a status of 404 () https://s.yimg.com/uu/api/res/1.2/jSzZgE8awpnl1iK5ewhp_Q--~B/Zmk9c3RyaW07aD0zODY7cHlvZmY9MDtxPTgwO3c9NDQwO3NtPTE7YXBwaWQ9eXRhY2h5b24-/http://media.zenfs.com/en-US/homerun/the_huffington_post_584/62b07dba096985d3502d58f4d58e1374.cf.webp
(WARNING) 2018-11-09 09:36:32,428 inspector_log._OnMessage:26  DevTools console [network]: Failed to load resource: the server responded with a status of 404 () https://s.yimg.com/uu/api/res/1.2/jSzZgE8awpnl1iK5ewhp_Q--~B/Zmk9c3RyaW07aD0zODY7cHlvZmY9MDtxPTgwO3c9NDQwO3NtPTE7YXBwaWQ9eXRhY2h5b24-/http://media.zenfs.com/en-US/homerun/the_huffington_post_584/62b07dba096985d3502d58f4d58e1374.cf.webp
(WARNING) 2018-11-09 09:36:32,474 inspector_log._OnMessage:26  DevTools console [network]: Failed to load resource: the server responded with a status of 404 () https://s.yimg.com/uu/api/res/1.2/jSzZgE8awpnl1iK5ewhp_Q--~B/Zmk9c3RyaW07aD0zODY7cHlvZmY9MDtxPTgwO3c9NDQwO3NtPTE7YXBwaWQ9eXRhY2h5b24-/http://media.zenfs.com/en-US/homerun/the_huffington_post_584/62b07dba096985d3502d58f4d58e1374.cf.webp
(WARNING) 2018-11-09 09:36:32,514 inspector_log._OnMessage:26  DevTools console [network]: Failed to load resource: the server responded with a status of 404 () https://s.yimg.com/uu/api/res/1.2/jSzZgE8awpnl1iK5ewhp_Q--~B/Zmk9c3RyaW07aD0zODY7cHlvZmY9MDtxPTgwO3c9NDQwO3NtPTE7YXBwaWQ9eXRhY2h5b24-/http://media.zenfs.com/en-US/homerun/the_huffington_post_584/62b07dba096985d3502d58f4d58e1374.cf.webp
(WARNING) 2018-11-09 09:36:32,554 inspector_log._OnMessage:26  DevTools console [network]: Failed to load resource: the server responded with a status of 404 () https://s.yimg.com/uu/api/res/1.2/jSzZgE8awpnl1iK5ewhp_Q--~B/Zmk9c3RyaW07aD0zODY7cHlvZmY9MDtxPTgwO3c9NDQwO3NtPTE7YXBwaWQ9eXRhY2h5b24-/http://media.zenfs.com/en-US/homerun/the_huffington_post_584/62b07dba096985d3502d58f4d58e1374.cf.webp
(WARNING) 2018-11-09 09:36:32,714 inspector_log._OnMessage:26  DevTools console [network]: Failed to load resource: the server responded with a status of 404 () https://s.yimg.com/uu/api/res/1.2/jSzZgE8awpnl1iK5ewhp_Q--~B/Zmk9c3RyaW07aD0zODY7cHlvZmY9MDtxPTgwO3c9NDQwO3NtPTE7YXBwaWQ9eXRhY2h5b24-/http://media.zenfs.com/en-US/homerun/the_huffington_post_584/62b07dba096985d3502d58f4d58e1374.cf.webp
(WARNING) 2018-11-09 09:36:32,714 inspector_log._OnMessage:26  DevTools console [network]: Failed to load resource: the server responded with a status of 404 () https://s.yimg.com/uu/api/res/1.2/6.n3ljRQ816bRAG0h_0FxQ--~B/Zmk9c3RyaW07aD0zODY7cHlvZmY9MDtxPTgwO3c9NDQwO3NtPTE7YXBwaWQ9eXRhY2h5b24-/http://media.zenfs.com/en-US/homerun/aol_com_127/1ba4680c30464c5443d9709186dabfe8.cf.webp

This is from https://00e9e64baccf4548da0db5a796adb1534893171dd4f23501f2-apidata.googleusercontent.com/download/storage/v1/b/chromeos-autotest-results/o/256383742-chromeos-test%2Fchromeos6-row2-rack23-host1%2Fdebug%2Fautoserv.DEBUG?qk=AD5uMEtHN7AvW9xA7kovI18PkAo-QKkur1-PQhhwa3X-nhq4_nQbA_tlE939R_Vjc-pAD9wGErWT-dBeoWk6FVc2fbzdLcp9UNBqMp9eivSAgByf_MAQLXnXtx2YBaDC5iwKF8BWIoyysmgM3ggwe9dbiMgPKwrN7SG2csD04jUhrys02_Cdgv-EDmZUHOCoxkSQZm7Hhpnsbz0fAgLpmOO8InMA7IaG-zanzZof1mgQ-2wR5nkmw0llDISfkojdtb5aYM77iP3uGvTDErvflDdtUdGLzl2_M--JL4TTW7ASQdyxZJj_lCsqUk-oLkVZPh7AOPEH4CRd0XDZgRsX-7v4_E0Cn-b5tYRzJGEenAX9DQF0OPAr02D3MoI-ndmpidPjOzBC6JNukezSnrVqsMlazuYYAsBUe3NNAGV9awwO4E-Z09B-0i5-QS2TXB6F4RxxXiyK7yL6gmV5kkrQgafhnppUQbk4_A0RrhxhjN6GzrTN8Gui4Y8MqnXS32aknbBqWVVlNcNKuy7gvaReIGo2wgERRvI_BlSXFgSF-G1NV98W-Bdy0CUVjwCQSp1hNLwPm8uJsECMmWRXNc5ud5SZln6uMGGkYgh3v8HjgXJDFjjP974wPImDM8lGjs6ynJcaTbf7nNSCEzdANgs2yc2Ov6SnrG55l0LkxxSgLVo7R9gEWlgV9oNZQWgQFYk8ApLQes-EireOtRgZUAj4i2JQpgqICMRc4fiCr2ZDPWPHXKil_qRQXLzqvuXwoDtXAM3VWY8Hm0e_mOpE3L79YdFnDZoo0f7iJ-DF5qtK1elQLv0cSLgE6ZcfGyvZJKswlb3oNrl7HVsB5K5aOaSky11pGoBUjqucQXzMWH2mPrzZUmH9-ITv_4jfI3AjhbD6XbpmHmPwuSgy .