Chromium 151 flipped MasterPrefs::eula_required from false to true, so a first run with no seed now stops on a blank terms-of-service dialog before the browser opens. The opt-out is written in two places that each run exactly once: the install leaf that runs during ISO finalization, and the one-time 3.x upgrade. A machine already on Quattro runs neither again, so it keeps the old seed and still meets the dialog the first time anyone launches Chromium, including from every user account created after the install.
The migration writes the same seed those two paths write. It compares before writing so the second user on a shared machine no-ops rather than repeating a machine-wide repair, and the literal is duplicated rather than sourced because a migration repairs the state of its own moment and must not drift when the seed later changes.
Co-Authored-By: Codex XHigh <noreply@openai.com>
