tl;dr: Google's Chrome team is using LLM-based agents (including Big Sleep and CodeMender) to automate vulnerability discovery, triage, and patching across the Chromium codebase, resulting in 1,072 security bugs fixed in Chrome 149 and 150—more than the previous 23 milestones combined. To keep pace, Google is shifting to two security releases per week, developing "dynamic patching" to avoid browser restarts, and accelerating memory-safety efforts via MiraclePtr expansion, spanification, and Rust migration. AI agents now also run in the CI/commit queue to catch vulnerabilities before code lands.