--- a/browser/base/content/test/plugins/browser_CTP_data_urls.js
+++ b/browser/base/content/test/plugins/browser_CTP_data_urls.js
@@ -63,17 +63,17 @@ add_task(function* () {
     let utils = content.QueryInterface(Components.interfaces.nsIInterfaceRequestor)
                        .getInterface(Components.interfaces.nsIDOMWindowUtils);
     utils.sendMouseEvent("mousedown", left, top, 0, 1, 0, false, 0, 0);
     utils.sendMouseEvent("mouseup", left, top, 0, 1, 0, false, 0, 0);
   });
   yield promise;
 
   // Simulate clicking the "Allow Always" button.
-  let condition = function() !PopupNotifications.getNotification("click-to-play-plugins", gTestBrowser).dismissed &&
+  let condition = () => !PopupNotifications.getNotification("click-to-play-plugins", gTestBrowser).dismissed &&
     PopupNotifications.panel.firstChild;
   yield promiseForCondition(condition);
   PopupNotifications.panel.firstChild._primaryButton.click();
 
   // check plugin state
   pluginInfo = yield promiseForPluginInfo("test");
   ok(pluginInfo.activated, "Test 1b, plugin should be activated");
 });
@@ -180,17 +180,17 @@ add_task(function* () {
     let utils = content.QueryInterface(Components.interfaces.nsIInterfaceRequestor)
                        .getInterface(Components.interfaces.nsIDOMWindowUtils);
     utils.sendMouseEvent("mousedown", left, top, 0, 1, 0, false, 0, 0);
     utils.sendMouseEvent("mouseup", left, top, 0, 1, 0, false, 0, 0);
   });
   yield promise;
 
   // Simulate clicking the "Allow Always" button.
-  let condition = function() !PopupNotifications.getNotification("click-to-play-plugins", gTestBrowser).dismissed &&
+  let condition = () => !PopupNotifications.getNotification("click-to-play-plugins", gTestBrowser).dismissed &&
     PopupNotifications.panel.firstChild;
   yield promiseForCondition(condition);
   PopupNotifications.panel.firstChild._primaryButton.click();
 
   // check plugin state
   pluginInfo = yield promiseForPluginInfo("test");
   ok(pluginInfo.activated, "Test 3a, plugin should be activated");
 
@@ -238,17 +238,17 @@ add_task(function* () {
     let utils = content.QueryInterface(Components.interfaces.nsIInterfaceRequestor)
                        .getInterface(Components.interfaces.nsIDOMWindowUtils);
     utils.sendMouseEvent("mousedown", left, top, 0, 1, 0, false, 0, 0);
     utils.sendMouseEvent("mouseup", left, top, 0, 1, 0, false, 0, 0);
   });
   yield promise;
 
   // Simulate clicking the "Allow Always" button.
-  let condition = function() !PopupNotifications.getNotification("click-to-play-plugins", gTestBrowser).dismissed &&
+  let condition = () => !PopupNotifications.getNotification("click-to-play-plugins", gTestBrowser).dismissed &&
     PopupNotifications.panel.firstChild;
   yield promiseForCondition(condition);
   PopupNotifications.panel.firstChild._primaryButton.click();
 
   // check plugin state
   pluginInfo = yield promiseForPluginInfo("test");
   ok(pluginInfo.activated, "Test 4a, plugin should be activated");
 });

--- a/browser/base/content/test/plugins/browser_CTP_drag_drop.js
+++ b/browser/base/content/test/plugins/browser_CTP_drag_drop.js
@@ -78,17 +78,17 @@ add_task(function* () {
     let left = (bounds.left + bounds.right) / 2;
     let top = (bounds.top + bounds.bottom) / 2;
     let utils = content.QueryInterface(Components.interfaces.nsIInterfaceRequestor)
                        .getInterface(Components.interfaces.nsIDOMWindowUtils);
     utils.sendMouseEvent("mousedown", left, top, 0, 1, 0, false, 0, 0);
     utils.sendMouseEvent("mouseup", left, top, 0, 1, 0, false, 0, 0);
   });
 
-  let condition = function() !PopupNotifications.getNotification("click-to-play-plugins", gNewWindow.gBrowser.selectedBrowser).dismissed && gNewWindow.PopupNotifications.panel.firstChild;
+  let condition = () => !PopupNotifications.getNotification("click-to-play-plugins", gNewWindow.gBrowser.selectedBrowser).dismissed && gNewWindow.PopupNotifications.panel.firstChild;
   yield promiseForCondition(condition);
 });
 
 add_task(function* () {
   // Click the activate button on doorhanger to make sure it works
   gNewWindow.PopupNotifications.panel.firstChild._primaryButton.click();
 
   let pluginInfo = yield promiseForPluginInfo("test", gNewWindow.gBrowser.selectedBrowser);

--- a/browser/base/content/test/plugins/browser_bug787619.js
+++ b/browser/base/content/test/plugins/browser_bug787619.js
@@ -47,17 +47,17 @@ add_task(function* () {
     utils.sendMouseEvent("mouseup", left, top, 0, 1, 0, false, 0, 0);
   });
   yield promise;
 
   // check plugin state
   pluginInfo = yield promiseForPluginInfo("plugin");
   ok(!pluginInfo.activated, "1b plugin should not be activated");
 
-  let condition = function() !PopupNotifications.getNotification("click-to-play-plugins", gTestBrowser).dismissed &&
+  let condition = () => !PopupNotifications.getNotification("click-to-play-plugins", gTestBrowser).dismissed &&
     PopupNotifications.panel.firstChild;
   yield promiseForCondition(condition);
   PopupNotifications.panel.firstChild._primaryButton.click();
 
   // check plugin state
   pluginInfo = yield promiseForPluginInfo("plugin");
   ok(pluginInfo.activated, "plugin should be activated");
 

--- a/browser/base/content/test/plugins/browser_pluginnotification.js
+++ b/browser/base/content/test/plugins/browser_pluginnotification.js
@@ -234,17 +234,17 @@ add_task(function* () {
     let left = (bounds.left + bounds.right) / 2;
     let top = (bounds.top + bounds.bottom) / 2;
     let utils = content.QueryInterface(Components.interfaces.nsIInterfaceRequestor)
                        .getInterface(Components.interfaces.nsIDOMWindowUtils);
     utils.sendMouseEvent("mousedown", left, top, 0, 1, 0, false, 0, 0);
     utils.sendMouseEvent("mouseup", left, top, 0, 1, 0, false, 0, 0);
   });
 
-  let condition = function() !PopupNotifications.getNotification("click-to-play-plugins", gTestBrowser).dismissed;
+  let condition = () => !PopupNotifications.getNotification("click-to-play-plugins", gTestBrowser).dismissed;
   yield promiseForCondition(condition);
 });
 
 // Tests that clicking the text of the overlay activates the plugin
 add_task(function* () {
   yield promiseTabLoadEvent(gBrowser.selectedTab, gTestRoot + "plugin_test.html");
 
   // Work around for delayed PluginBindingAttached
@@ -264,17 +264,17 @@ add_task(function* () {
     let left = (bounds.left + bounds.right) / 2;
     let top = (bounds.top + bounds.bottom) / 2;
     let utils = content.QueryInterface(Components.interfaces.nsIInterfaceRequestor)
                        .getInterface(Components.interfaces.nsIDOMWindowUtils);
     utils.sendMouseEvent("mousedown", left, top, 0, 1, 0, false, 0, 0);
     utils.sendMouseEvent("mouseup", left, top, 0, 1, 0, false, 0, 0);
   });
 
-  let condition = function() !PopupNotifications.getNotification("click-to-play-plugins", gTestBrowser).dismissed;
+  let condition = () => !PopupNotifications.getNotification("click-to-play-plugins", gTestBrowser).dismissed;
   yield promiseForCondition(condition);
 });
 
 // Tests that clicking the box of the overlay activates the doorhanger
 // (just to be thorough)
 add_task(function* () {
   yield promiseTabLoadEvent(gBrowser.selectedTab, gTestRoot + "plugin_test.html");
 
@@ -291,17 +291,17 @@ add_task(function* () {
     let doc = content.document;
     let plugin = doc.getElementById("test");
     let utils = content.QueryInterface(Components.interfaces.nsIInterfaceRequestor)
                        .getInterface(Components.interfaces.nsIDOMWindowUtils);
     utils.sendMouseEvent("mousedown", 50, 50, 0, 1, 0, false, 0, 0);
     utils.sendMouseEvent("mouseup", 50, 50, 0, 1, 0, false, 0, 0);
   });
 
-  let condition = function() !PopupNotifications.getNotification("click-to-play-plugins", gTestBrowser).dismissed &&
+  let condition = () => !PopupNotifications.getNotification("click-to-play-plugins", gTestBrowser).dismissed &&
     PopupNotifications.panel.firstChild;
   yield promiseForCondition(condition);
   PopupNotifications.panel.firstChild._primaryButton.click();
 
   pluginInfo = yield promiseForPluginInfo("test");
   ok(pluginInfo.activated, "Test 19e, Plugin should not be activated");
 
   clearAllPluginPermissions();
@@ -374,17 +374,17 @@ add_task(function* () {
     let left = (bounds.left + bounds.right) / 2;
     let top = (bounds.top + bounds.bottom) / 2;
     let utils = content.QueryInterface(Components.interfaces.nsIInterfaceRequestor)
                        .getInterface(Components.interfaces.nsIDOMWindowUtils);
     utils.sendMouseEvent("mousedown", left, top, 0, 1, 0, false, 0, 0);
     utils.sendMouseEvent("mouseup", left, top, 0, 1, 0, false, 0, 0);
   });
 
-  let condition = function() !notification.dismissed && !!PopupNotifications.panel.firstChild;
+  let condition = () => !notification.dismissed && !!PopupNotifications.panel.firstChild;
   yield promiseForCondition(condition);
   PopupNotifications.panel.firstChild._primaryButton.click();
 
   pluginInfo = yield promiseForPluginInfo("test");
   ok(pluginInfo.activated, "Test 20c, plugin should be activated");
 
   result = ContentTask.spawn(gTestBrowser, {}, function* () {
     let doc = content.document;

--- a/browser/base/content/test/plugins/browser_plugins_added_dynamically.js
+++ b/browser/base/content/test/plugins/browser_plugins_added_dynamically.js
@@ -109,17 +109,17 @@ add_task(function* () {
 
   yield promiseForNotificationShown(notification);
 
   is(notification.options.pluginData.size, 1, "Should be one plugin action");
 
   let pluginInfo = yield promiseForPluginInfo("pluginone");
   ok(!pluginInfo.activated, "Test 8, test plugin should be activated");
 
-  let condition = function() !notification.dismissed &&
+  let condition = () => !notification.dismissed &&
     PopupNotifications.panel.firstChild;
   yield promiseForCondition(condition);
 
   // "click" the button to activate the Test plugin
   PopupNotifications.panel.firstChild._primaryButton.click();
 
   pluginInfo = yield promiseForPluginInfo("pluginone");
   ok(pluginInfo.activated, "Test 9, test plugin should be activated");

--- a/browser/base/content/test/plugins/browser_private_clicktoplay.js
+++ b/browser/base/content/test/plugins/browser_private_clicktoplay.js
@@ -114,17 +114,17 @@ function test2a() {
 
   // Simulate clicking the "Allow Now" button.
   let promiseShown = BrowserTestUtils.waitForEvent(PopupNotifications.panel,
                                                    "Shown");
   popupNotification.reshow();
   promiseShown.then(() => {
     PopupNotifications.panel.firstChild._secondaryButton.click();
 
-    let condition = function() objLoadingContent.activated;
+    let condition = () => objLoadingContent.activated;
     waitForCondition(condition, test2b, "Test 2a, Waited too long for plugin to activate");
   });
 }
 
 function test2b() {
   createPrivateWindow(test2c, gHttpTestRoot + "plugin_test.html");
 }
 
@@ -164,17 +164,17 @@ function test3a() {
 
   // Simulate clicking the "Allow Always" button.
   let promiseShown = BrowserTestUtils.waitForEvent(PopupNotifications.panel,
                                                    "Shown");
   popupNotification.reshow();
   promiseShown.then(() => {
     PopupNotifications.panel.firstChild._secondaryButton.click();
 
-    let condition = function() objLoadingContent.activated;
+    let condition = () => objLoadingContent.activated;
     waitForCondition(condition, test3b, "Test 3a, Waited too long for plugin to activate");
   });
 }
 
 function test3b() {
   createPrivateWindow(test3c, gHttpTestRoot + "plugin_test.html");
 }