diff -r 000000000000 -r 6474c204b198 browser/metro/base/content/startui/RemoteTabsView.js
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/browser/metro/base/content/startui/RemoteTabsView.js	Wed Dec 31 06:09:35 2014 +0100
@@ -0,0 +1,143 @@
+// -*- Mode: js2; tab-width: 2; indent-tabs-mode: nil; js2-basic-offset: 2; js2-skip-preprocessor-directives: t; -*-
+/* 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";
+
+const Cu = Components.utils;
+
+Cu.import("resource://services-sync/main.js");
+Cu.import("resource://gre/modules/PlacesUtils.jsm", this);
+
+/**
+ * Wraps a list/grid control implementing nsIDOMXULSelectControlElement and
+ * fills it with the user's synced tabs.
+ *
+ * Note, the Sync module takes care of initializing the sync service. We should
+ * not make calls that start sync or sync tabs since this module loads really
+ * early during startup.
+ *
+ * @param    aSet         Control implementing nsIDOMXULSelectControlElement.
+ * @param    aSetUIAccess The UI element that should be hidden when Sync is
+ *                          disabled. Must sanely support 'hidden' attribute.
+ *                          You may only have one UI access point at this time.
+ */
+function RemoteTabsView(aSet, aSetUIAccessList) {
+  View.call(this, aSet);
+
+  this._uiAccessElements = aSetUIAccessList;
+
+  // Sync uses special voodoo observers.
+  // If you want to change this code, talk to the fx-si team
+  Weave.Svc.Obs.add("weave:service:sync:finish", this);
+  Weave.Svc.Obs.add("weave:service:start-over", this);
+
+  if (this.isSyncEnabled() ) {
+    this.populateGrid();
+  }
+  else {
+    this.setUIAccessVisible(false);
+  }
+}
+
+RemoteTabsView.prototype = Util.extend(Object.create(View.prototype), {
+  _set: null,
+  _uiAccessElements: [],
+
+  handleItemClick: function tabview_handleItemClick(aItem) {
+    let url = aItem.getAttribute("value");
+    StartUI.goToURI(url);
+  },
+
+  observe: function(subject, topic, data) {
+    switch (topic) {
+      case "weave:service:sync:finish":
+        this.populateGrid();
+        break;
+      case "weave:service:start-over":
+        this.setUIAccessVisible(false);
+        break;
+    }
+  },
+
+  setUIAccessVisible: function setUIAccessVisible(aVisible) {
+    for (let elem of this._uiAccessElements) {
+      elem.hidden = !aVisible;
+    }
+  },
+
+  getIcon: function (iconUri, defaultIcon) {
+    try {
+      let iconURI = Weave.Utils.makeURI(iconUri);
+      return PlacesUtils.favicons.getFaviconLinkForIcon(iconURI).spec;
+    } catch(ex) {
+      // Do nothing.
+    }
+
+    // Just give the provided default icon or the system's default.
+    return defaultIcon || PlacesUtils.favicons.defaultFavicon.spec;
+  },
+
+  populateGrid: function populateGrid() {
+
+    let tabsEngine = Weave.Service.engineManager.get("tabs");
+    let list = this._set;
+    let seenURLs = new Set();
+    let localURLs = tabsEngine.getOpenURLs();
+
+    // Clear grid, We don't know what has happened to tabs since last sync
+    // Also can result in duplicate tabs(bug 864614)
+    this._set.clearAll();
+    let show = false;
+    for (let [guid, client] in Iterator(tabsEngine.getAllClients())) {
+      client.tabs.forEach(function({title, urlHistory, icon}) {
+        let url = urlHistory[0];
+        if (!url || getOpenURLs.has(url) || seenURLs.has(url)) {
+          return;
+        }
+        seenURLs.add(url);
+        show = true;
+
+        // If we wish to group tabs by client, we should be looking for records
+        //  of {type:client, clientName, class:{mobile, desktop}} and will
+        //  need to readd logic to reset seenURLs for each client.
+
+        let item = this._set.appendItem((title || url), url);
+        item.setAttribute("iconURI", this.getIcon(icon));
+
+      }, this);
+    }
+    this.setUIAccessVisible(show);
+    this._set.arrangeItems();
+  },
+
+  destruct: function destruct() {
+    Weave.Svc.Obs.remove("weave:engine:sync:finish", this);
+    Weave.Svc.Obs.remove("weave:service:logout:start-over", this);
+    View.prototype.destruct.call(this);
+  },
+
+  isSyncEnabled: function isSyncEnabled() {
+    return (Weave.Status.checkSetup() != Weave.CLIENT_NOT_CONFIGURED);
+  }
+
+});
+
+let RemoteTabsStartView = {
+  _view: null,
+  get _grid() { return document.getElementById("start-remotetabs-grid"); },
+
+  init: function init() {
+    let vbox = document.getElementById("start-remotetabs");
+    let uiList = [vbox];
+    this._view = new RemoteTabsView(this._grid, uiList);
+    this._grid.removeAttribute("fade");
+  },
+
+  uninit: function uninit() {
+    if (this._view) {
+      this._view.destruct();
+    }
+  },
+};