text: (async function(testRunner) {
    const {page, session, dp} = await testRunner.startURL(
        'https://devtools.oopif-a.test:8443/inspector-protocol/resources/coi-with-iframe.php',
        `Tests that the attachedToTarget message is dispatched to all attached sessions`);
  
    await dp.Target.enable();
    await dp.Target.setAutoAttach(
        {autoAttach: true, waitForDebuggerOnStart: false, flatten: true});
    const session1Attached = dp.Target.onceAttachedToTarget().then(
        () => testRunner.log('session 1 attached'));
  
    const dp2 = (await page.createSession()).protocol;
    await dp2.Target.setAutoAttach(
        {autoAttach: true, waitForDebuggerOnStart: false, flatten: true});
    const session2Attached = dp2.Target.onceAttachedToTarget().then(
        () => testRunner.log('session 2 attached'));
  
    // This will force the iframe to navigate out-of-process.
    await session.evaluate(
        'document.getElementById(\'iframe\').src=\'https://devtools.oopif-b.test:8443/inspector-protocol/resources/corp-iframe.php\'');
  
    await Promise.all([session1Attached, session2Attached]);
    testRunner.completeTest();
  })
  