diff -r 000000000000 -r 6474c204b198 browser/metro/modules/ContentUtil.jsm
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/browser/metro/modules/ContentUtil.jsm	Wed Dec 31 06:09:35 2014 +0100
@@ -0,0 +1,106 @@
+/* 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/. */
+"use strict";
+
+this.EXPORTED_SYMBOLS = ["ContentUtil"];
+
+const XHTML_NS = "http://www.w3.org/1999/xhtml";
+const nsIDOMKeyEvent = Components.interfaces.nsIDOMKeyEvent;
+
+this.ContentUtil = {
+  populateFragmentFromString: function populateFragmentFromString(fragment, str) {
+    let re = /^([^#]*)#(\d+)\b([^#]*)/,
+        document = fragment.ownerDocument,
+        // the remaining arguments are our {text, className} values
+        replacements = Array.slice(arguments, 2),
+        match;
+
+    // walk over the string, building textNode/spans as nec. with replacement content
+    // note that #1,#2 etc. may not appear in numerical order in the string
+    while ((match = re.exec(str))) {
+      let [mstring,pre,num,post] = match,
+          replaceText = "",
+          replaceClass,
+          idx = num-1; // markers are 1-based, replacement indices 0 based
+
+      str = str.substring(re.lastIndex+mstring.length);
+
+      if (pre)
+          fragment.appendChild(document.createTextNode(pre));
+
+      if (replacements[idx]) {
+        replaceText = replacements[idx].text;
+        let spanNode = document.createElementNS(XHTML_NS, "span");
+        spanNode.appendChild(document.createTextNode(replaceText));
+        // add class to the span when provided
+        if(replacements[idx].className)
+          spanNode.classList.add(replacements[idx].className);
+
+        fragment.appendChild(spanNode);
+      } else {
+        // put it back if no replacement was provided
+        fragment.appendChild(document.createTextNode("#"+num));
+      }
+
+      if(post)
+        fragment.appendChild(document.createTextNode(post));
+    }
+    if(str)
+      fragment.appendChild(document.createTextNode(str));
+
+    return fragment;
+  },
+
+  // Pass several objects in and it will combine them all into the first object and return it.
+  // NOTE: Deep copy is not supported
+  extend: function extend() {
+    // copy reference to target object
+    let target = arguments[0] || {};
+    let length = arguments.length;
+
+    if (length === 1) {
+      return target;
+    }
+
+    // Handle case when target is a string or something
+    if (typeof target != "object" && typeof target != "function") {
+      target = {};
+    }
+
+    for (let i = 1; i < length; i++) {
+      // Only deal with non-null/undefined values
+      let options = arguments[i];
+      if (options != null) {
+        // Extend the base object
+        for (let name in options) {
+          let copy = options[name];
+
+          // Prevent never-ending loop
+          if (target === copy)
+            continue;
+
+          if (copy !== undefined)
+            target[name] = copy;
+        }
+      }
+    }
+
+    // Return the modified object
+    return target;
+  },
+
+  // Checks if a keycode is used for list navigation.
+  isNavigationKey: function (keyCode) {
+    let navigationKeys = [
+      nsIDOMKeyEvent.DOM_VK_DOWN,
+      nsIDOMKeyEvent.DOM_VK_UP,
+      nsIDOMKeyEvent.DOM_VK_LEFT,
+      nsIDOMKeyEvent.DOM_VK_RIGHT,
+      nsIDOMKeyEvent.DOM_VK_PAGE_UP,
+      nsIDOMKeyEvent.DOM_VK_PAGE_DOWN,
+      nsIDOMKeyEvent.DOM_VK_ESCAPE];
+
+    return navigationKeys.indexOf(keyCode) != -1;
+  }
+};