Tests that dispostion for client-requested navigation is properly reported.
New window
{
    disposition : newWindow
    frameId : <string>
    reason : anchorClick
    url : http://127.0.0.1:8000/inspector-protocol/page/resources/frame-requested-navigation-disposition.html?done
}
New tab
{
    disposition : newTab
    frameId : <string>
    reason : anchorClick
    url : http://127.0.0.1:8000/inspector-protocol/page/resources/frame-requested-navigation-disposition.html?done
}
Current tab
{
    disposition : currentTab
    frameId : <string>
    reason : anchorClick
    url : http://127.0.0.1:8000/inspector-protocol/page/resources/frame-requested-navigation-disposition.html?done
}