问chrome.browserAction.setIcon什么也不做

EN

// Get the behavior of the plugin; the default is set to "onClick", the other option is "alwaysOn"
chrome.storage.sync.get({
    extensionBehavior: 'onClick'
}, function(items) {
    if(items.extensionBehavior == 'onClick'){
      chrome.browserAction.setIcon({path: "blue-logo.png"});
      chrome.browserAction.onClicked.addListener(function() {
        // When the extension icon is clicked, send a message to the content script
        chrome.tabs.query({active: true, currentWindow: true}, function(tabs) {
          chrome.tabs.sendMessage(tabs[0].id, {"message": tabs[0].url}, function(response){});
        });
      });
    }
    else {
      chrome.browserAction.setIcon({path: "red-logo.png"});
      chrome.tabs.onUpdated.addListener(function (tabId, changeInfo, tab) {          
        if (changeInfo.status == 'complete') {
           // When the HTML loads, send a message to the content script
           chrome.tabs.query({active: true, currentWindow: true}, function(tabs){
             chrome.tabs.sendMessage(tabs[0].id, {"message": tabs[0].url}, function(response){});
           });
        }
      });
    }
});