--- a/testing/mochitest/runtestsb2g.py
+++ b/testing/mochitest/runtestsb2g.py
@@ -54,19 +54,18 @@ class B2GMochitest(Mochitest):
         if self.OOP:
             OOP_script = """
 let specialpowers = {};
 let loader = Cc["@mozilla.org/moz/jssubscript-loader;1"].getService(Ci.mozIJSSubScriptLoader);
 loader.loadSubScript("chrome://specialpowers/content/SpecialPowersObserver.js", specialpowers);
 let specialPowersObserver = new specialpowers.SpecialPowersObserver();
 specialPowersObserver.init();
 
-let fl = container.QueryInterface(Ci.nsIFrameLoaderOwner).frameLoader;
-fl.activateRemoteFrame();
-let mm = fl.messageManager;
+let mm = container.QueryInterface(Ci.nsIFrameLoaderOwner).frameLoader.messageManager;
+container.focus();
 mm.addMessageListener("SPPrefService", specialPowersObserver);
 mm.addMessageListener("SPProcessCrashService", specialPowersObserver);
 mm.addMessageListener("SPPingService", specialPowersObserver);
 mm.addMessageListener("SpecialPowers.Quit", specialPowersObserver);
 mm.addMessageListener("SPPermissionManager", specialPowersObserver);
 
 mm.loadFrameScript(CHILD_LOGGER_SCRIPT, true);
 mm.loadFrameScript(CHILD_SCRIPT_API, true);
@@ -80,18 +79,37 @@ specialPowersObserver._isFrameScriptLoad
         # the test-container apps's iframe to the mochitest URL.
         self.automation.test_script = """
 const CHILD_SCRIPT = "chrome://specialpowers/content/specialpowers.js";
 const CHILD_SCRIPT_API = "chrome://specialpowers/content/specialpowersAPI.js";
 const CHILD_LOGGER_SCRIPT = "chrome://specialpowers/content/MozillaLogger.js";
 
 let homescreen = document.getElementById('homescreen');
 let container = homescreen.contentWindow.document.getElementById('test-container');
-container.setAttribute('mozapp', 'http://mochi.test:8888/manifest.webapp');
+
+function openWindow(aEvent) {
+  var popupIframe = aEvent.detail.frameElement;
+  popupIframe.setAttribute('style', 'position: absolute; left: 0; top: 300px; background: white; ');
+
+  popupIframe.addEventListener('mozbrowserclose', function(e) {
+    container.parentNode.removeChild(popupIframe);
+    container.focus();
+  });
 
+  // yes, the popup can call window.open too!
+  popupIframe.addEventListener('mozbrowseropenwindow', openWindow);
+
+  popupIframe.addEventListener('mozbrowserloadstart', function(e) {
+    popupIframe.focus();
+  });
+
+  container.parentNode.appendChild(popupIframe);
+}
+
+container.addEventListener('mozbrowseropenwindow', openWindow);
 %s
 
 container.src = '%s';
 """ % (OOP_script, testURL)
 
     def buildProfile(self, options):
         # preferences
         prefs = {}