1 files changed, 10 insertions, 11 deletions
diff --git a/toolkit/mozapps/extensions/test/xpinstall/browser_badargs2.js b/toolkit/mozapps/extensions/test/xpinstall/browser_badargs2.js
index 7137df318..25e1586c8 100644
--- a/toolkit/mozapps/extensions/test/xpinstall/browser_badargs2.js
+++ b/toolkit/mozapps/extensions/test/xpinstall/browser_badargs2.js
@@ -11,15 +11,12 @@ function test() {
   }));
   gBrowser.selectedTab = gBrowser.addTab();
 
-  ContentTask.spawn(gBrowser.selectedBrowser, null, function() {
-    return new Promise(resolve => {
-      addEventListener("load", () => {
-        content.addEventListener("InstallTriggered", () => {
-          resolve(content.document.getElementById("return").textContent);
-        });
-      }, true);
-    });
-  }).then(page_loaded);
+  function loadListener() {
+    gBrowser.selectedBrowser.removeEventListener("load", loadListener, true);
+    gBrowser.contentWindow.addEventListener("InstallTriggered", page_loaded, false);
+  }
+
+  gBrowser.selectedBrowser.addEventListener("load", loadListener, true);
 
   // In non-e10s the exception in the content page would trigger a test failure
   if (!gMultiProcessBrowser)
@@ -28,8 +25,10 @@ function test() {
   gBrowser.loadURI(TESTROOT + "installtrigger.html?" + triggers);
 }
 
-function page_loaded(result) {
-  is(result, "exception", "installTrigger should have failed");
+function page_loaded() {
+  gBrowser.contentWindow.removeEventListener("InstallTriggered", page_loaded, false);
+  var doc = gBrowser.contentDocument;
+  is(doc.getElementById("return").textContent, "exception", "installTrigger should have failed");
 
   // In non-e10s the exception from the page is thrown after the event so we
   // have to spin the event loop to make sure it arrives so expectUncaughtException