"use strict"; add_task(async () => { function httpURL(filename, host = "https://example.com/") { let root = getRootDirectory(gTestPath).replace( "chrome://mochitests/content/", host ); return root + filename; } await SpecialPowers.pushPrefEnv({ set: [["dom.meta-viewport.enabled", true]], }); const fissionWindow = await BrowserTestUtils.openNewBrowserWindow({ fission: true, }); const url = httpURL( "test_visual_viewport_in_oopif.html", "http://mochi.test:8888/" ); const crossOriginIframeUrl = httpURL("visual_viewport_in_child.html"); try { await BrowserTestUtils.withNewTab( { gBrowser: fissionWindow.gBrowser, url }, async browser => { await SpecialPowers.spawn( browser, [crossOriginIframeUrl], async iframeUrl => { const iframe = content.document.getElementById("iframe"); iframe.setAttribute("src", iframeUrl); let { width, height } = await new Promise(resolve => { content.window.addEventListener("message", msg => { resolve(msg.data); }); }); is( width, 300, "visualViewport.width shouldn't be affected in out-of-process iframes" ); is( height, 300, "visualViewport.height shouldn't be affected in out-of-process iframes" ); } ); } ); } finally { await BrowserTestUtils.closeWindow(fissionWindow); } });