diff -r 000000000000 -r 6474c204b198 browser/metro/components/DownloadManagerUI.js
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/browser/metro/components/DownloadManagerUI.js	Wed Dec 31 06:09:35 2014 +0100
@@ -0,0 +1,43 @@
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+const Ci = Components.interfaces;
+
+Components.utils.import("resource://gre/modules/XPCOMUtils.jsm");
+Components.utils.import("resource://gre/modules/Services.jsm");
+
+// -----------------------------------------------------------------------
+// Download Manager UI
+// -----------------------------------------------------------------------
+
+function DownloadManagerUI() { }
+
+DownloadManagerUI.prototype = {
+  classID: Components.ID("{93db15b1-b408-453e-9a2b-6619e168324a}"),
+
+  show: function show(aWindowContext, aID, aReason, aUsePrivateUI) {
+    if (!aReason)
+      aReason = Ci.nsIDownloadManagerUI.REASON_USER_INTERACTED;
+
+    let browser = Services.wm.getMostRecentWindow("navigator:browser");
+    if (browser)
+      browser.showDownloadManager(aWindowContext, aID, aReason);
+  },
+
+  get visible() {
+    // For now there is no Download Manager UI.
+    return false;
+  },
+
+  getAttention: function getAttention() {
+    if (this.visible)
+      this.show(null, null, null);
+    else
+      throw Cr.NS_ERROR_UNEXPECTED;
+  },
+
+  QueryInterface: XPCOMUtils.generateQI([Ci.nsIDownloadManagerUI])
+};
+
+this.NSGetFactory = XPCOMUtils.generateNSGetFactory([DownloadManagerUI]);