Chromium is open-source and the developers write pretty good commit messages about _why_ they're changing something. As for your example with --disable-feature

Chromium is open-source and the developers write pretty good commit messages about _why_ they're changing something. As for your example with --disable-features=Windows10CustomTitleBar, you can view the motivation for the relevant change here: https://source.chromium.org/chromium/chromium/src/+/549aa8ae8fd3d6bb6275ec1da07ed24b3c2a592a https://source.chromium.org/chromium/chromium/src/+/549aa8ae... It wasn't removed, it just changed. It's not a feature flag anymore, just a normal flag: --disable-windows10-custom-titlebar. This appears to be a purely technical decision. I am not even sure a PM was involved.