The engine speaks the DevTools Protocol
The browser now answers the standard DevTools protocol, the JSON command language that inspectors and headless automation tools speak to a page. Runtime.evaluate runs an expression and returns a real remote object (or a real exception), DOM.getDocument serialises the live tree, DOM.querySelector and DOM.getOuterHTML find and read elements, and CSS.getComputedStyleForNode reports an element''s resolved style - all served from the engine's actual DOM, JS and CSS state rather than a canned response. This is the protocol half of DevTools; the debugger, a WebSocket transport and extension support are still ahead, so the sub-score moves honestly for what landed.