Tests that new-tab prerender targets (target_hint="_blank") get auto-attached properly.
{
    sessionId : <string>
    targetInfo : {
        attached : true
        browserContextId : <string>
        canAccessOpener : false
        subtype : prerender
        targetId : <string>
        title :
        type : page
        url :
    }
    waitingForDebugger : true
}
Navigation: http://devtools.oopif-a.test:8000/inspector-protocol/prerender/resources/empty.html