diff -r 000000000000 -r 6474c204b198 dom/browser-element/BrowserElementChild.js
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/dom/browser-element/BrowserElementChild.js	Wed Dec 31 06:09:35 2014 +0100
@@ -0,0 +1,58 @@
+/* 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";
+
+let { classes: Cc, interfaces: Ci, results: Cr, utils: Cu }  = Components;
+Cu.import("resource://gre/modules/Services.jsm");
+
+function debug(msg) {
+  //dump("BrowserElementChild - " + msg + "\n");
+}
+
+// NB: this must happen before we process any messages from
+// mozbrowser API clients.
+docShell.isActive = true;
+
+function parentDocShell(docshell) {
+  if (!docshell) {
+    return null;
+  }
+  let treeitem = docshell.QueryInterface(Ci.nsIDocShellTreeItem);
+  return treeitem.parent ? treeitem.parent.QueryInterface(Ci.nsIDocShell) : null;
+}
+
+function isTopBrowserElement(docShell) {
+  while (docShell) {
+    docShell = parentDocShell(docShell);
+    if (docShell && docShell.isBrowserOrApp) {
+      return false;
+    }
+  }
+  return true;
+}
+
+if (!('BrowserElementIsPreloaded' in this)) {
+  if (isTopBrowserElement(docShell) &&
+      Services.prefs.getBoolPref("dom.mozInputMethod.enabled")) {
+    try {
+      Services.scriptloader.loadSubScript("chrome://global/content/forms.js");
+    } catch (e) {
+    }
+  }
+
+  Services.scriptloader.loadSubScript("chrome://global/content/BrowserElementPanning.js");
+  ContentPanning.init();
+
+  Services.scriptloader.loadSubScript("chrome://global/content/BrowserElementChildPreload.js");
+} else {
+  ContentPanning.init();
+}
+
+var BrowserElementIsReady = true;
+
+let infos = sendSyncMessage('browser-element-api:call',
+                            { 'msg_name': 'hello' })[0];
+docShell.QueryInterface(Ci.nsIDocShellTreeItem).name = infos.name;
+docShell.setFullscreenAllowed(infos.fullscreenAllowed);