diff -r 000000000000 -r 6474c204b198 browser/metro/components/ContentDispatchChooser.js
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/browser/metro/components/ContentDispatchChooser.js	Wed Dec 31 06:09:35 2014 +0100
@@ -0,0 +1,38 @@
+/* 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;
+const Cu = Components.utils;
+
+Cu.import("resource://gre/modules/XPCOMUtils.jsm");
+Cu.import("resource://gre/modules/Services.jsm");
+
+function ContentDispatchChooser() {}
+
+ContentDispatchChooser.prototype =
+{
+  classID: Components.ID("5a072a22-1e66-4100-afc1-07aed8b62fc5"),
+
+  QueryInterface: XPCOMUtils.generateQI([Ci.nsIContentDispatchChooser]),
+
+  ask: function ask(aHandler, aWindowContext, aURI, aReason) {
+    let window = null;
+    try {
+      if (aWindowContext)
+        window = aWindowContext.getInterface(Ci.nsIDOMWindow);
+    } catch (e) { /* it's OK to not have a window */ }
+
+    let bundle = Services.strings.createBundle("chrome://mozapps/locale/handling/handling.properties");
+
+    let title = bundle.GetStringFromName("protocol.title");
+    let message = bundle.GetStringFromName("protocol.description");
+
+    let open = Services.prompt.confirm(window, title, message);
+    if (open)
+      aHandler.launchWithURI(aURI, aWindowContext);
+  }
+};
+
+this.NSGetFactory = XPCOMUtils.generateNSGetFactory([ContentDispatchChooser]);
+