diff -r 000000000000 -r 6474c204b198 browser/components/customizableui/test/browser_946320_tabs_from_other_computers.js
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/browser/components/customizableui/test/browser_946320_tabs_from_other_computers.js	Wed Dec 31 06:09:35 2014 +0100
@@ -0,0 +1,124 @@
+/* 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 Preferences = Cu.import("resource://gre/modules/Preferences.jsm", {}).Preferences;
+
+let tmp = {};
+Cu.import("resource://gre/modules/FxAccounts.jsm", tmp);
+Cu.import("resource://gre/modules/FxAccountsCommon.js", tmp);
+Cu.import("resource://services-sync/browserid_identity.js", tmp);
+let {FxAccounts, BrowserIDManager, DATA_FORMAT_VERSION, CERT_LIFETIME} = tmp;
+let fxaSyncIsEnabled = Weave.Service.identity instanceof BrowserIDManager;
+
+add_task(function() {
+  yield PanelUI.show({type: "command"});
+
+  let historyButton = document.getElementById("history-panelmenu");
+  let historySubview = document.getElementById("PanelUI-history");
+  let subviewShownPromise = subviewShown(historySubview);
+  EventUtils.synthesizeMouseAtCenter(historyButton, {});
+  yield subviewShownPromise;
+
+  let tabsFromOtherComputers = document.getElementById("sync-tabs-menuitem2");
+  is(tabsFromOtherComputers.hidden, true, "The Tabs From Other Computers menuitem should be hidden when sync isn't enabled.");
+
+  let hiddenPanelPromise = promisePanelHidden(window);
+  PanelUI.hide();
+  yield hiddenPanelPromise;
+
+  // Part 2 - When Sync is enabled the menuitem should be shown.
+  yield configureIdentity();
+  yield PanelUI.show({type: "command"});
+
+  subviewShownPromise = subviewShown(historySubview);
+  EventUtils.synthesizeMouseAtCenter(historyButton, {});
+  yield subviewShownPromise;
+
+  is(tabsFromOtherComputers.hidden, false, "The Tabs From Other Computers menuitem should be shown when sync is enabled.");
+
+  let syncPrefBranch = new Preferences("services.sync.");
+  syncPrefBranch.resetBranch("");
+  Services.logins.removeAllLogins();
+
+  hiddenPanelPromise = promisePanelHidden(window);
+  PanelUI.toggle({type: "command"});
+  yield hiddenPanelPromise;
+
+  if (fxaSyncIsEnabled) {
+    yield fxAccounts.signOut();
+  }
+});
+
+function configureIdentity() {
+  // do the FxAccounts thang...
+  configureFxAccountIdentity();
+
+  if (fxaSyncIsEnabled) {
+    return Weave.Service.identity.initializeWithCurrentIdentity().then(() => {
+      // need to wait until this identity manager is readyToAuthenticate.
+      return Weave.Service.identity.whenReadyToAuthenticate.promise;
+    });
+  }
+
+  Weave.Service.createAccount("john@doe.com", "mysecretpw",
+                              "challenge", "response");
+  Weave.Service.identity.account = "john@doe.com";
+  Weave.Service.identity.basicPassword = "mysecretpw";
+  Weave.Service.identity.syncKey = Weave.Utils.generatePassphrase();
+  Weave.Svc.Prefs.set("firstSync", "newAccount");
+  Weave.Service.persistLogin();
+  return Promise.resolve();
+}
+
+// Configure an instance of an FxAccount identity provider with the specified
+// config (or the default config if not specified).
+function configureFxAccountIdentity() {
+  let user = {
+    assertion: "assertion",
+    email: "email",
+    kA: "kA",
+    kB: "kB",
+    sessionToken: "sessionToken",
+    uid: "user_uid",
+    verified: true,
+  };
+
+  let token = {
+    endpoint: Weave.Svc.Prefs.get("tokenServerURI"),
+    duration: 300,
+    id: "id",
+    key: "key",
+    // uid will be set to the username.
+  };
+
+  let MockInternal = {};
+  let mockTSC = { // TokenServerClient
+    getTokenFromBrowserIDAssertion: function(uri, assertion, cb) {
+      token.uid = "username";
+      cb(null, token);
+    },
+  };
+
+  let authService = Weave.Service.identity;
+  authService._fxaService = new FxAccounts(MockInternal);
+
+  authService._fxaService.internal.currentAccountState.signedInUser = {
+    version: DATA_FORMAT_VERSION,
+    accountData: user
+  }
+  authService._fxaService.internal.currentAccountState.getCertificate = function(data, keyPair, mustBeValidUntil) {
+    this.cert = {
+      validUntil: authService._fxaService.internal.now() + CERT_LIFETIME,
+      cert: "certificate",
+    };
+    return Promise.resolve(this.cert.cert);
+  };
+
+  authService._tokenServerClient = mockTSC;
+  // Set the "account" of the browserId manager to be the "email" of the
+  // logged in user of the mockFXA service.
+  authService._account = user.email;
+}