This would allow us to click links on Google search.

Should be a straightfoward implementation - refer to the implementation of fn Assign if it's not clear.

Spec: https://html.spec.whatwg.org/multipage/browsers.html#dom-location-replace
Files: components/script/dom/webidls/Location.webidl, components/script/dom/location.rs
Test: tests/wpt/web-platform-tests/html/browsers/history/the-location-interface/location_replace.html