popup.js

var websites = {"badware": "http://www.google.com/safebrowsing/report_badware/?url=", "webspam": "https://www.google.com/webmasters/tools/spamreportform?spamurl=", "phishing": "http://www.google.com/safebrowsing/report_phish/?url="};

var options = document.querySelectorAll("div#options div.option");

for (var i = 0; i < options.length; i++) {
  options[i].innerText = chrome.i18n.getMessage("report_"+options[i].id);
  options[i].onclick = function(a) {
    var id = this.id;
    chrome.tabs.query({
      lastFocusedWindow: true,
      active: true
    }, function(tab){
      chrome.tabs.create({
        url: websites[id]+encodeURI(tab[0].url),
        index: tab[0].index + 1
      });
    });
  }
}