--- a/browser/base/content/test/social/browser_social_chatwindow.js
+++ b/browser/base/content/test/social/browser_social_chatwindow.js
@@ -248,22 +248,22 @@ var tests = {
   },
 
   testMultipleProviderChat: function(next) {
     // test incomming chats from all providers
     let port0 = openChat(Social.providers[0], function() {
       let port1 = openChat(Social.providers[1], function() {
         let port2 = openChat(Social.providers[2], function() {
           let chats = document.getElementById("pinnedchats");
-          waitForCondition(function() chats.children.length == Social.providers.length,
+          waitForCondition(() => chats.children.length == Social.providers.length,
             function() {
               ok(true, "one chat window per provider opened");
               // test logout of a single provider
               port2.postMessage({topic: "test-logout"});
-              waitForCondition(function() chats.children.length == Social.providers.length - 1,
+              waitForCondition(() => chats.children.length == Social.providers.length - 1,
                 function() {
                   Task.spawn(closeAllChats).then(next);
                 },
                 "chat window didn't close");
             }, "chat windows did not open");
         });
       });
     });
@@ -283,17 +283,17 @@ var tests = {
         case "test-init-done":
           info("open first chat window");
           port.postMessage({topic: "test-worker-chat", data: chatUrl});
           break;
         case "got-chatbox-message":
           ok(true, "got a chat window opened");
           if (opened) {
             port.postMessage({topic: "test-logout"});
-            waitForCondition(function() document.getElementById("pinnedchats").firstChild == null,
+            waitForCondition(() => document.getElementById("pinnedchats").firstChild == null,
                              function() {
                               next();
                              },
                              "chat windows didn't close");
           } else {
             // open a second chat window
             opened = true;
             port.postMessage({topic: "test-worker-chat", data: chatUrl+"?id=1"});

--- a/browser/base/content/test/social/browser_social_chatwindowfocus.js
+++ b/browser/base/content/test/social/browser_social_chatwindowfocus.js
@@ -30,17 +30,17 @@ function openChatViaSidebarMessage(port,
 }
 
 function openChatViaWorkerMessage(port, data, callback) {
   // sadly there is no message coming back to tell us when the chat has
   // been opened, so we wait until one appears.
   let chatbar = getChatBar();
   let numExpected = chatbar.childElementCount + 1;
   port.postMessage({topic: "test-worker-chat", data: data});
-  waitForCondition(function() chatbar.childElementCount == numExpected,
+  waitForCondition(() => chatbar.childElementCount == numExpected,
                    function() {
                       // so the child has been added, but we don't know if it
                       // has been intialized - re-request it and the callback
                       // means it's done.  Minimized, same as the worker.
                       chatbar.openChat(SocialSidebar.provider.origin,
                                        SocialSidebar.provider.name,
                                        data,
                                        "minimized",
@@ -102,17 +102,17 @@ function test() {
   tab.linkedBrowser.addEventListener("load", function tabLoad(event) {
     tab.linkedBrowser.removeEventListener("load", tabLoad, true);
     // before every test we focus the input field.
     let preSubTest = function(cb) {
       // XXX - when bug 604289 is fixed it should be possible to just do:
       // tab.linkedBrowser.contentWindow.focus()
       // but instead we must do:
       tab.linkedBrowser.contentDocument.getElementById("theinput").focus();
-      waitForCondition(function() isTabFocused(), cb, "tab should have focus");
+      waitForCondition(() => isTabFocused(), cb, "tab should have focus");
     }
     let postSubTest = function(cb) {
       Task.spawn(closeAllChats).then(cb);
     }
     // and run the tests.
     runSocialTestWithProvider(manifest, function (finishcb) {
       SocialSidebar.show();
       runSocialTests(tests, preSubTest, postSubTest, function () {
@@ -139,17 +139,17 @@ var tests = {
         is(chatbar.childElementCount, 1, "exactly 1 chat open");
         ok(isTabFocused(), "tab should still be focused");
         // re-request the same chat via a message.
         openChatViaSidebarMessage(port, {stealFocus: 1}, function() {
           is(chatbar.childElementCount, 1, "still exactly 1 chat open");
           ok(isTabFocused(), "tab should still be focused");
           // re-request the same chat via user event.
           openChatViaUser();
-          waitForCondition(function() isChatFocused(chatbar.selectedChat),
+          waitForCondition(() => isChatFocused(chatbar.selectedChat),
                            function() {
             is(chatbar.childElementCount, 1, "still exactly 1 chat open");
             is(chatbar.selectedChat, chatbar.firstElementChild, "chat should be selected");
             next();
           }, "chat should be focused");
         });
       });
     });
@@ -157,16 +157,16 @@ var tests = {
 
   // In this test we arrange for the sidebar to open the chat via a simulated
   // click.  This should cause the new chat to be opened and focused.
   testFocusWhenViaUser: function(next) {
     startTestAndWaitForSidebar(function(port) {
       let chatbar = getChatBar();
       openChatViaUser();
       ok(chatbar.firstElementChild, "chat opened");
-      waitForCondition(function() isChatFocused(chatbar.selectedChat),
+      waitForCondition(() => isChatFocused(chatbar.selectedChat),
                        function() {
         is(chatbar.selectedChat, chatbar.firstElementChild, "chat is selected");
         next();
       }, "chat should be focused");
     });
   },
 };

--- a/browser/base/content/test/social/browser_social_errorPage.js
+++ b/browser/base/content/test/social/browser_social_errorPage.js
@@ -129,17 +129,17 @@ var tests = {
       openChat(
         manifest.sidebarURL, /* empty html page */
         function() { // the panel api callback
           panelCallbackCount++;
         },
         function() { // the "load" callback.
           todo_is(panelCallbackCount, 0, "Bug 833207 - should be no callback when error page loads.");
           let chat = getChatBar().selectedChat;
-          waitForCondition(function() chat.content != null && chat.contentDocument.documentURI.indexOf("about:socialerror?mode=tryAgainOnly")==0,
+          waitForCondition(() => chat.content != null && chat.contentDocument.documentURI.indexOf("about:socialerror?mode=tryAgainOnly")==0,
                            function() {
                             chat.close();
                             next();
                             },
                            "error page didn't appear");
         }
       );
     });
@@ -157,24 +157,24 @@ var tests = {
       null,
       function() { // the "load" callback.
         let chat = getChatBar().selectedChat;
         is(chat.contentDocument.documentURI, url, "correct url loaded");
         // toggle to a detached window.
         chat.swapWindows().then(
           chat => {
             ok(!!chat.content, "we have chat content 1");
-            waitForCondition(function() chat.content != null && chat.contentDocument.readyState == "complete",
+            waitForCondition(() => chat.content != null && chat.contentDocument.readyState == "complete",
                              function() {
               // now go offline and reload the chat - about:socialerror should be loaded.
               goOffline().then(function() {
                 ok(!!chat.content, "we have chat content 2");
                 chat.contentDocument.location.reload();
                 info("chat reload called");
-                waitForCondition(function() chat.contentDocument.documentURI.indexOf("about:socialerror?mode=tryAgainOnly")==0,
+                waitForCondition(() => chat.contentDocument.documentURI.indexOf("about:socialerror?mode=tryAgainOnly")==0,
                                  function() {
                                   chat.close();
                                   next();
                                   },
                                  "error page didn't appear");
               });
             }, "swapped window loaded");
           }

--- a/browser/base/content/test/social/browser_social_marks.js
+++ b/browser/base/content/test/social/browser_social_marks.js
@@ -152,34 +152,34 @@ var tests = {
           case "test-init-done":
             ok(true, "test-init-done received");
             ok(provider.profile.userName, "profile was set by test worker");
             // first click marks the page, second click opens the page. We have to
             // synthesize so the command event happens
             EventUtils.synthesizeMouseAtCenter(btn, {});
             // wait for the button to be marked, click to open panel
             is(btn.panel.state, "closed", "panel should not be visible yet");
-            waitForCondition(function() btn.isMarked, function() {
+            waitForCondition(() => btn.isMarked, function() {
               EventUtils.synthesizeMouseAtCenter(btn, {});
             }, "button is marked");
             break;
           case "got-social-panel-visibility":
             ok(true, "got the panel message " + e.data.result);
             if (e.data.result == "shown") {
               // unmark the page via the button in the page
               ensureFrameLoaded(btn.content).then(() => {
                 let doc = btn.contentDocument;
                 let unmarkBtn = doc.getElementById("unmark");
                 ok(unmarkBtn, "testMarkPanel - got the panel unmark button");
                 EventUtils.sendMouseEvent({type: "click"}, unmarkBtn, btn.contentWindow);
               });
             } else {
               // page should no longer be marked
               port.close();
-              waitForCondition(function() !btn.isMarked, function() {
+              waitForCondition(() => !btn.isMarked, function() {
                 // cleanup after the page has been unmarked
                 ensureBrowserTabClosed(tab).then(() => {
                   ok(btn.disabled, "button is disabled");
                   next();
                 });
               }, "button unmarked");
             }
             break;
@@ -240,17 +240,17 @@ var tests = {
       ok(!btn.disabled, "button is enabled");
       port.onmessage = function (e) {
         let topic = e.data.topic;
         switch (topic) {
           case "test-init-done":
             ok(true, "test-init-done received");
             ok(provider.profile.userName, "profile was set by test worker");
             port.postMessage({topic: "test-logout"});
-            waitForCondition(function() !provider.profile.userName,
+            waitForCondition(() => !provider.profile.userName,
                 function() {
                   // when the provider has not indicated to us that a user is
                   // logged in, the first click opens the page.
                   EventUtils.synthesizeMouseAtCenter(btn, {});
                 },
                 "profile was unset by test worker");
             break;
           case "got-social-panel-visibility":
@@ -263,17 +263,17 @@ var tests = {
                 let doc = btn.contentDocument;
                 let unmarkBtn = doc.getElementById("unmark");
                 ok(unmarkBtn, "testMarkPanelLoggedOut - got the panel unmark button");
                 EventUtils.sendMouseEvent({type: "click"}, unmarkBtn, btn.contentWindow);
               });
             } else {
               // page should no longer be marked
               port.close();
-              waitForCondition(function() !btn.isMarked, function() {
+              waitForCondition(() => !btn.isMarked, function() {
                 // cleanup after the page has been unmarked
                 ensureBrowserTabClosed(tab).then(() => {
                   ok(btn.disabled, "button is disabled");
                   next();
                 });
               }, "button unmarked");
             }
             break;

--- a/browser/base/content/test/social/browser_social_multiworker.js
+++ b/browser/base/content/test/social/browser_social_multiworker.js
@@ -47,17 +47,17 @@ var tests = {
       };
       port.postMessage({topic: "test-init"});
     }
 
     for (let p of Social.providers) {
       oneWorkerTest(p);
     }
 
-    waitForCondition(function() messageReceived == Social.providers.length,
+    waitForCondition(() => messageReceived == Social.providers.length,
                      next, "received messages from all workers",
                      /* increase timeout because shutting down a child process is slow */ 60);
   },
 
    testMultipleWorkerEnabling: function(next) {
      // test that all workers are enabled when we allow multiple workers
      for (let p of Social.providers) {
        ok(p.enabled, "provider enabled");

--- a/browser/base/content/test/social/browser_social_window.js
+++ b/browser/base/content/test/social/browser_social_window.js
@@ -91,17 +91,17 @@ var tests = {
 
   // Check when providers are enabled and social is turned on at startup.
   testEnabledStartup: function(cbnext) {
     setManifestPref("social.manifest.test", manifest);
     ok(!SocialSidebar.opened, "sidebar is closed initially");
     SocialService.addProvider(manifest, function() {
       SocialService.addProvider(manifest2, function (provider) {
         SocialSidebar.show();
-        waitForCondition(function() SocialSidebar.opened,
+        waitForCondition(() => SocialSidebar.opened,
                      function() {
           ok(SocialSidebar.opened, "first window sidebar is open");
           openWindowAndWaitForInit(window, function(w1) {
             ok(w1.SocialSidebar.opened, "new window sidebar is open");
             ok(SocialService.hasEnabledProviders, "providers are enabled");
             checkSocialUI(w1);
             // now init is complete, open a second window
             openWindowAndWaitForInit(window, function(w2) {
@@ -135,17 +135,17 @@ var tests = {
     ok(!SocialSidebar.opened, "sidebar is closed initially");
     ok(!Services.prefs.prefHasUserValue("social.sidebar.provider"), "global state unset");
     // mimick no session state in opener so we exercise the global state via pref
     SessionStore.deleteWindowValue(window, "socialSidebar");
     ok(!SessionStore.getWindowValue(window, "socialSidebar"), "window state unset");
     SocialService.addProvider(manifest, function() {
       openWindowAndWaitForInit(window, function(w1) {
         w1.SocialSidebar.show();
-        waitForCondition(function() w1.SocialSidebar.opened,
+        waitForCondition(() => w1.SocialSidebar.opened,
                      function() {
           ok(Services.prefs.prefHasUserValue("social.sidebar.provider"), "global state set");
           ok(!SocialSidebar.opened, "1. main sidebar is still closed");
           ok(w1.SocialSidebar.opened, "1. window sidebar is open");
           closeWindow(w1, function() {
             // this time, the global state should cause the sidebar to be opened
             // in the new window
             openWindowAndWaitForInit(window, function(w1) {

--- a/browser/base/content/test/social/head.js
+++ b/browser/base/content/test/social/head.js
@@ -149,17 +149,17 @@ function runSocialTestWithProvider(manif
       }
 
       // If we've added all the providers we need, call the callback to start
       // the tests (and give it a callback it can call to finish them)
       if (providersAdded == manifests.length) {
         registerCleanupFunction(function () {
           finishSocialTest(true);
         });
-        waitForCondition(function() provider.enabled,
+        waitForCondition(() => provider.enabled,
                          function() {
           info("provider has been enabled");
           callback(finishSocialTest);
         }, "providers added and enabled");
       }
     });
   });
 }
@@ -584,17 +584,17 @@ function resizeAndCheckWidths(first, sec
   let count = checks.length;
   let [width, numExpectedVisible, why] = checks.shift();
   info("<< Check " + count + ": " + why);
   info(count + ": " + "resizing window to " + width + ", expect " + numExpectedVisible + " visible items");
   resizeWindowToChatAreaWidth(width, function(sizedOk) {
     checkPopup();
     ok(sizedOk, count+": window resized correctly");
     function collapsedObserver(r, m) {
-      if ([first, second, third].filter(function(item) !item.collapsed).length == numExpectedVisible) {
+      if ([first, second, third].filter(item => !item.collapsed).length == numExpectedVisible) {
         if (m) {
           m.disconnect();
         }
         ok(true, count + ": " + "correct number of chats visible");
         info(">> Check " + count);
         executeSoon(function() {
           resizeAndCheckWidths(first, second, third, checks, cb);
         });