<html class="reftest-wait"> <meta name="viewport" content="width=device-width minimum-scale=0.25 initial-scale=1.0"> <style> html, body { margin: 0; width: 100%; height: 100%; scrollbar-width: none; } div { position: absolute; } .B { width: 200%; height: 400%; background: white; } .C { width: 200%; height: 200%; background: green; } </style> <div class="B"></div> <div class="C"></div> <script> document.addEventListener('MozReftestInvalidate', () => { // The page here is twice the width of the ICB, and four times the height. // We want the layout viewport to be expanded to be twice the width and // height of the ICB (to maintain aspect ratio), rather than four times the // height. // To test this, scroll to the end of the layout scroll range. // If the layout viewport is expanded too much, we have no layout scroll // range, so nothing will happen, and a green area will remain in view. // If the layout viewport is expanded to the desired size, a white area // will be scrolled into view, matching the reference page. window.scrollTo(window.scrollMaxX, window.scrollMaxY); document.documentElement.classList.remove('reftest-wait'); }); </script> </html>