Expose navigator.product and navigator.appCodeName constants to workers

LayoutTests/fast/workers/resources/worker-navigator.js

 function log(message)
 {
     document.getElementById("result").innerHTML += message + "<br>";
 }
 
 if (window.testRunner) {
     testRunner.dumpAsText();
     testRunner.waitUntilDone();
 }
 
 var worker = createWorker();
 worker.postMessage("eval typeof navigator");
 worker.postMessage("eval navigator");
 worker.postMessage("eval navigator.appName");
 worker.postMessage("eval navigator.appVersion.indexOf('WebKit') != 0");
 worker.postMessage("eval typeof navigator.platform");
 worker.postMessage("eval navigator.userAgent.indexOf('WebKit') != 0");
 worker.postMessage("eval typeof navigator.onLine");
+worker.postMessage("eval navigator.appCodeName === 'Mozilla'");
+worker.postMessage("eval navigator.product === 'Gecko'");
 worker.postMessage("eval foo//bar");
 
 worker.onmessage = function(evt) {
     if (!/foo\/\/bar/.test(evt.data))
         log(evt.data.replace(new RegExp("/.*LayoutTests"), "<...>"));
     else {
         log("DONE");
         if (window.testRunner)
             testRunner.notifyDone();
     }
 }