--- a/testing/talos/talos/startup_test/tresize/addon/content/tresize.js
+++ b/testing/talos/talos/startup_test/tresize/addon/content/tresize.js
@@ -11,27 +11,27 @@ var windowSize = 425;
 var resizeIncrement = 2;
 var count = 0;
 var max = 300;
 
 var dumpDataSet = false;
 var doneCallback = null;
 
 function painted() {
-  window.gBrowser.removeEventListener("MozAfterPaint", painted, true);
+  window.removeEventListener("MozAfterPaint", painted, true);
   var paintTime = window.performance.now();
   Profiler.pause("resize " + count);
   dataSet[count].end = paintTime;
   setTimeout(resizeCompleted, 20);
 }
 
 function resizeTest() {
   try {
     windowSize += resizeIncrement;
-    window.gBrowser.addEventListener("MozAfterPaint", painted, true);
+    window.addEventListener("MozAfterPaint", painted, true);
     Profiler.resume("resize " + count);
     dataSet[count] = {'start': window.performance.now()};
     window.resizeTo(windowSize,windowSize);
   } catch(ex) { finish([ex + '\n']); }
 }
 
 function testCompleted() {
   try {

--- a/testing/talos/talos/startup_test/tresize/addon/install.rdf
+++ b/testing/talos/talos/startup_test/tresize/addon/install.rdf
@@ -12,9 +12,10 @@
         <em:maxVersion>*</em:maxVersion>
     </Description>
 </em:targetApplication>
 
 <!-- Optional Items -->
 <em:creator>Joel Maher</em:creator>
 <em:description>https://wiki.mozilla.org/Buildbot/Talos/Tests</em:description>
 <em:homepageURL>https://wiki.mozilla.org/Buildbot/Talos/Tests</em:homepageURL>
+<em:multiprocessCompatible>true</em:multiprocessCompatible>
 </Description></RDF>