Yes, I didn't mean to imply that Chrome wasn't multi-process all along. But Chrome historically used it more for fault isolation (= crashing one tab doesn't cra

Yes, I didn't mean to imply that Chrome wasn't multi-process all along. But Chrome historically used it more for fault isolation (= crashing one tab doesn't crash them all) rather than security isolation. Historically window.open() would (usually) open a new tab that actually ran in the same process, and iframes ran in the same process, so getting any arbitrary site running in the same process as yours was easy.