Deferred Page Swap in Blink and Chromium

The provided text explains deferred page swap, an internal mechanism in Chromium and Blink designed to facilitate smooth cross-document view transitions. By intentionally delaying the navigation commit, the browser allows the outgoing document enough time to fire a pageswap event and capture visual snapshots of its current state. These captured GPU resources are cached in Viz and identified by a unique token, which the incoming document later uses to create seamless animations. The implementation involves a commit-deferring condition that balances visual fidelity with performance, utilizing a four-second timeout to prevent navigation hangs. Furthermore, the documents detail how Mojo interfaces and resource management classes coordinate this process across the browser, renderer, and GPU processes. Security is maintained by restricting these transitions to same-origin navigations without cross-origin redirects to protect sensitive data.