Bug 361911: Unable to install updates on startup after dismissing notifications. r=robstrong

toolkit/mozapps/extensions/content/extensions.js

@@ -2140,8 +2140,11 @@ function installUpdatesAll() {
   if (!isXPInstallEnabled())
     return;
 
-  if (gUpdatesOnly)
+  if (gUpdatesOnly) {
-    document.getElementById("addonsMsg").removeCurrentNotification();
+    var notifications = document.getElementById("addonsMsg");
+    if (notifications.currentNotification)
+      notifications.removeCurrentNotification();
+  }
 
   var items = [];
   var children = gExtensionsView.children;