text: chrome.runtime.onInstalled.addListener(function() {
      chrome.storage.sync.set({color: ''}, function() {
        console.log('The color is green.');
      });
      chrome.declarativeContent.onPageChanged.removeRules(undefined, function() {
        chrome.declarativeContent.onPageChanged.addRules([{
          conditions: [new chrome.declarativeContent.PageStateMatcher({
            pageUrl: {hostEquals: 'www.google.com'},
          })
          ],
              actions: [new chrome.declarativeContent.ShowPageAction()]
        }]);
      });
    });