title: Chrome.webNavigation.onBeforeNavigate Cannot read property 'callback' of undefined
body: <p>I want to use the callback of chrome.webNavigation.onBeforeNavigate to get the frame information such as frameId and parentFrameId.</p>
  
  <p>code in background page:</p>
  
  <pre><code>chrome.webNavigation.onBeforeNavigate.addListener(onBeforeNaviCallback);
  
  function onBeforeNaviCallback(detail){
  
      console.log("frameId" +detail.frameId); 
  
  };//end of onBefore 
  </code></pre>
  
  <p>There is alway an error:</p>
  
  <pre><code> Error in event handler for 'webNavigation.onBeforeNavigate': Cannot read property 'callback' of undefined TypeError: Cannot read property 'callback' of undefined
          at Event.dispatch_ (event_bindings:342:58)
          at dispatchArgs (event_bindings:214:26)
          at Object.chromeHidden.Event.dispatchEvent (event_bindings:223:7)
  </code></pre>