查验url

 <script>
      // Called when the url of a tab changes.
      function checkForValidUrl(tabId, changeInfo, tab) {
        // If the letter 'g' is found in the tab's URL...
        chrome.tabs.getSelected(null, function(tab) { 
        // Toggle the pinned status
		if(tab.url.indexOf("renren.com")>-1&&!tab.pinned){
        	//chrome.tabs.update(tab.id, {'pinned': !tab.pinned});
			}
      });
      };

      // Listen for any changes to the URL of any tab.
      chrome.tabs.onUpdated.addListener(checkForValidUrl);
    </script>