Yesterday I pushed Chrome 69 to my test server and it seems like for the Wikipedia pages I test the first visual change moved something like 100 ms. I'm gonna rollback and check if the timings go back and then roll forward again and collect more data.
We can see that on some wikis (Chinese, Japanese, Russian) first paint is 20-30% slower when upgrading to Chrome 69 (from 68).
Upstream: https://bugs.chromium.org/p/chromium/issues/detail?id=887205