diff -r 000000000000 -r 6474c204b198 toolkit/components/downloads/test/unit/downloads_manifest.js
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/toolkit/components/downloads/test/unit/downloads_manifest.js	Wed Dec 31 06:09:35 2014 +0100
@@ -0,0 +1,24 @@
+/* Any copyright is dedicated to the Public Domain.
+  http://creativecommons.org/publicdomain/zero/1.0/ */
+
+// Shared functions for files testing Bug 593815
+
+Components.utils.import("resource://gre/modules/XPCOMUtils.jsm");
+
+const Cc = Components.classes;
+const Ci = Components.interfaces;
+
+function HelperAppDlg() { }
+HelperAppDlg.prototype = {
+  QueryInterface: XPCOMUtils.generateQI([Ci.nsIHelperAppLauncherDialog]),
+  classID: Components.ID("49456eda-4dc4-4d1a-b8e8-0b94749bf99e"),
+  show: function (launcher, ctx, reason) {
+    launcher.MIMEInfo.preferredAction = Ci.nsIMIMEInfo.saveToDisk;
+    launcher.launchWithApplication(null, false);
+  },
+
+  promptForSaveToFile: function (launcher, ctx, defaultFile, suggestedExtension, forcePrompt) { }
+}
+
+
+this.NSGetFactory = XPCOMUtils.generateNSGetFactory([HelperAppDlg]);