--- a/devtools/.eslintrc
+++ b/devtools/.eslintrc
@@ -66,17 +66,17 @@
     // Allow trailing commas for easy list extension.  Having them does not
     // impair readability, but also not required either.
     "comma-dangle": 0,
     // Enforce spacing before and after comma
     "comma-spacing": [2, {"before": false, "after": true}],
     // Enforce one true comma style.
     "comma-style": [2, "last"],
     // Warn about cyclomatic complexity in functions.
-    "complexity": 2,
+    "complexity": [2, 35],
     // Require return statements to either always or never specify values.
     "consistent-return": 2,
     // Don't warn for inconsistent naming when capturing this (not so important
     // with auto-binding fat arrow functions).
     "consistent-this": 0,
     // Enforce curly brace conventions for all control statements.
     "curly": 2,
     // Don't require a default case in switch statements. Avoid being forced to
@@ -172,18 +172,16 @@
     // Disallow empty statements. This will report an error for:
     // try { something(); } catch (e) {}
     // but will not report it for:
     // try { something(); } catch (e) { /* Silencing the error because ...*/ }
     // which is a valid use case.
     "no-empty": 2,
     // Disallow the use of empty character classes in regular expressions.
     "no-empty-character-class": 2,
-    // Disallow use of labels for anything other then loops and switches.
-    "no-empty-label": 2,
     // Disallow use of eval(). We have other APIs to evaluate code in content.
     "no-eval": 2,
     // Disallow assigning to the exception in a catch block.
     "no-ex-assign": 2,
     // Disallow adding to native types
     "no-extend-native": 2,
     // Disallow unnecessary function binding.
     "no-extra-bind": 2,
@@ -319,34 +317,32 @@
     "semi": [2, "always"],
     // Enforce spacing after semicolons.
     "semi-spacing": [2, {"before": false, "after": true}],
     // Don't require to sort variables within the same declaration block.
     // Anyway, one-var is disabled.
     "sort-vars": 0,
     // Deprecated, will be removed in 1.0.
     "space-after-function-name": 0,
-    // Require a space after keywords.
-    "space-after-keywords": [2, "always"],
+    // Require a space around all keywords.
+    "keyword-spacing": 2,
     // Require a space before the start brace of a block.
     "space-before-blocks": [2, "always"],
     // Deprecated, will be removed in 1.0.
     "space-before-function-parentheses": 0,
     // Disallow space before function opening parenthesis.
     "space-before-function-paren": [2, "never"],
     // Disable the rule that checks if spaces inside {} and [] are there or not.
     // Our code is split on conventions, and it'd be nice to have 2 rules
     // instead, one for [] and one for {}. So, disabling until we write them.
     "space-in-brackets": 0,
     // Disallow spaces inside parentheses.
     "space-in-parens": [2, "never"],
     // Require spaces around operators, except for a|0.
     "space-infix-ops": [2, {"int32Hint": true}],
-    // Require a space after return, throw, and case.
-    "space-return-throw-case": 2,
     // Require spaces before/after unary operators (words on by default,
     // nonwords off by default).
     "space-unary-ops": [2, { "words": true, "nonwords": false }],
     // Deprecated, will be removed in 1.0.
     "space-unary-word-ops": 0,
     // Require a space immediately following the // in a line comment.
     "spaced-comment": [2, "always"],
     // Require "use strict" to be defined globally in the script.
@@ -391,17 +387,17 @@
     "no-invalid-regexp": 0,
     // disallow irregular whitespace outside of strings and comments
     "no-irregular-whitespace": 0,
     // disallow usage of __iterator__ property
     "no-iterator": 0,
     // disallow labels that share a name with a variable
     "no-label-var": 0,
     // disallow use of labeled statements
-    "no-labels": 0,
+    "no-labels": 2,
     // disallow unnecessary nested blocks
     "no-lone-blocks": 0,
     // disallow creation of functions within loops
     "no-loop-func": 0,
     // disallow negation of the left operand of an in expression
     "no-negated-in-lhs": 0,
     // disallow use of new operator when not part of the assignment or
     // comparison

--- a/devtools/client/aboutdebugging/modules/worker.js
+++ b/devtools/client/aboutdebugging/modules/worker.js
@@ -37,17 +37,17 @@ exports.debugWorker = function(client, w
  *
  * @param {DebuggerClient} client
  * @return {Object}
  *         - {Array} registrations
  *           Array of ServiceWorkerRegistrationActor forms
  *         - {Array} workers
  *           Array of WorkerActor forms
  */
-exports.getWorkerForms = Task.async(function*(client) {
+exports.getWorkerForms = Task.async(function* (client) {
   let registrations = [];
   let workers = [];
 
   try {
     // List service worker registrations
     ({ registrations } =
       yield client.mainRoot.listServiceWorkerRegistrations());
 

--- a/devtools/client/animationinspector/animation-controller.js
+++ b/devtools/client/animationinspector/animation-controller.js
@@ -30,17 +30,17 @@ const L10N = new LocalizationHelper(STRI
 
 // Global toolbox/inspector, set when startup is called.
 var gToolbox, gInspector;
 
 /**
  * Startup the animationinspector controller and view, called by the sidebar
  * widget when loading/unloading the iframe into the tab.
  */
-var startup = Task.async(function*(inspector) {
+var startup = Task.async(function* (inspector) {
   gInspector = inspector;
   gToolbox = inspector.toolbox;
 
   // Don't assume that AnimationsPanel is defined here, it's in another file.
   if (!typeof AnimationsPanel === "undefined") {
     throw new Error("AnimationsPanel was not loaded in the " +
                     "animationinspector window");
   }
@@ -51,17 +51,17 @@ var startup = Task.async(function*(inspe
   yield AnimationsController.initialize();
   yield AnimationsPanel.initialize();
 });
 
 /**
  * Shutdown the animationinspector controller and view, called by the sidebar
  * widget when loading/unloading the iframe into the tab.
  */
-var shutdown = Task.async(function*() {
+var shutdown = Task.async(function* () {
   yield AnimationsController.destroy();
   // Don't assume that AnimationsPanel is defined here, it's in another file.
   if (typeof AnimationsPanel !== "undefined") {
     yield AnimationsPanel.destroy();
   }
   gToolbox = gInspector = null;
 });
 
@@ -74,17 +74,17 @@ function destroy() {
 }
 
 /**
  * Get all the server-side capabilities (traits) so the UI knows whether or not
  * features should be enabled/disabled.
  * @param {Target} target The current toolbox target.
  * @return {Object} An object with boolean properties.
  */
-var getServerTraits = Task.async(function*(target) {
+var getServerTraits = Task.async(function* (target) {
   let config = [
     { name: "hasToggleAll", actor: "animations",
       method: "toggleAll" },
     { name: "hasToggleSeveral", actor: "animations",
       method: "toggleSeveral" },
     { name: "hasSetCurrentTime", actor: "animationplayer",
       method: "setCurrentTime" },
     { name: "hasMutationEvents", actor: "animations",
@@ -130,17 +130,17 @@ var getServerTraits = Task.async(functio
  *     // do something with player
  *   }
  * }
  */
 var AnimationsController = {
   PLAYERS_UPDATED_EVENT: "players-updated",
   ALL_ANIMATIONS_TOGGLED_EVENT: "all-animations-toggled",
 
-  initialize: Task.async(function*() {
+  initialize: Task.async(function* () {
     if (this.initialized) {
       yield this.initialized.promise;
       return;
     }
     this.initialized = promise.defer();
 
     this.onPanelVisibilityChange = this.onPanelVisibilityChange.bind(this);
     this.onNewNodeFront = this.onNewNodeFront.bind(this);
@@ -164,17 +164,17 @@ var AnimationsController = {
     }
 
     this.startListeners();
     yield this.onNewNodeFront();
 
     this.initialized.resolve();
   }),
 
-  destroy: Task.async(function*() {
+  destroy: Task.async(function* () {
     if (!this.initialized) {
       return;
     }
 
     if (this.destroyed) {
       yield this.destroyed.promise;
       return;
     }
@@ -210,23 +210,23 @@ var AnimationsController = {
   },
 
   isPanelVisible: function() {
     return gToolbox.currentToolId === "inspector" &&
            gInspector.sidebar &&
            gInspector.sidebar.getCurrentTabID() == "animationinspector";
   },
 
-  onPanelVisibilityChange: Task.async(function*() {
+  onPanelVisibilityChange: Task.async(function* () {
     if (this.isPanelVisible()) {
       this.onNewNodeFront();
     }
   }),
 
-  onNewNodeFront: Task.async(function*() {
+  onNewNodeFront: Task.async(function* () {
     // Ignore if the panel isn't visible or the node selection hasn't changed.
     if (!this.isPanelVisible() ||
         this.nodeFront === gInspector.selection.nodeFront) {
       return;
     }
 
     this.nodeFront = gInspector.selection.nodeFront;
     let done = gInspector.updating("animationscontroller");
@@ -260,17 +260,17 @@ var AnimationsController = {
 
   /**
    * Similar to toggleAll except that it only plays/pauses the currently known
    * animations (those listed in this.animationPlayers).
    * @param {Boolean} shouldPause True if the animations should be paused, false
    * if they should be played.
    * @return {Promise} Resolves when the playState has been changed.
    */
-  toggleCurrentAnimations: Task.async(function*(shouldPause) {
+  toggleCurrentAnimations: Task.async(function* (shouldPause) {
     if (this.traits.hasToggleSeveral) {
       yield this.animationsFront.toggleSeveral(this.animationPlayers,
                                                shouldPause);
     } else {
       // Fall back to pausing/playing the players one by one, which is bound to
       // introduce some de-synchronization.
       for (let player of this.animationPlayers) {
         if (shouldPause) {
@@ -283,17 +283,17 @@ var AnimationsController = {
   }),
 
   /**
    * Set all known animations' currentTimes to the provided time.
    * @param {Number} time.
    * @param {Boolean} shouldPause Should the animations be paused too.
    * @return {Promise} Resolves when the current time has been set.
    */
-  setCurrentTimeAll: Task.async(function*(time, shouldPause) {
+  setCurrentTimeAll: Task.async(function* (time, shouldPause) {
     if (this.traits.hasSetCurrentTimes) {
       yield this.animationsFront.setCurrentTimes(this.animationPlayers, time,
                                                  shouldPause);
     } else {
       // Fall back to pausing and setting the current time on each player, one
       // by one, which is bound to introduce some de-synchronization.
       for (let animation of this.animationPlayers) {
         if (shouldPause) {
@@ -304,17 +304,17 @@ var AnimationsController = {
     }
   }),
 
   /**
    * Set all known animations' playback rates to the provided rate.
    * @param {Number} rate.
    * @return {Promise} Resolves when the rate has been set.
    */
-  setPlaybackRateAll: Task.async(function*(rate) {
+  setPlaybackRateAll: Task.async(function* (rate) {
     if (this.traits.hasSetPlaybackRates) {
       // If the backend can set all playback rates at the same time, use that.
       yield this.animationsFront.setPlaybackRates(this.animationPlayers, rate);
     } else if (this.traits.hasSetPlaybackRate) {
       // Otherwise, fall back to setting each rate individually.
       for (let animation of this.animationPlayers) {
         yield animation.setPlaybackRate(rate);
       }
@@ -322,17 +322,17 @@ var AnimationsController = {
   }),
 
   // AnimationPlayerFront objects are managed by this controller. They are
   // retrieved when refreshAnimationPlayers is called, stored in the
   // animationPlayers array, and destroyed when refreshAnimationPlayers is
   // called again.
   animationPlayers: [],
 
-  refreshAnimationPlayers: Task.async(function*(nodeFront) {
+  refreshAnimationPlayers: Task.async(function* (nodeFront) {
     this.destroyAnimationPlayers();
 
     this.animationPlayers = yield this.animationsFront
                                       .getAnimationPlayersForNode(nodeFront);
 
     // Start listening for animation mutations only after the first method call
     // otherwise events won't be sent.
     if (!this.isListeningToMutations && this.traits.hasMutationEvents) {

--- a/devtools/client/animationinspector/animation-panel.js
+++ b/devtools/client/animationinspector/animation-panel.js
@@ -17,17 +17,17 @@ var $ = (selector, target = document) =>
 
 /**
  * The main animations panel UI.
  */
 var AnimationsPanel = {
   UI_UPDATED_EVENT: "ui-updated",
   PANEL_INITIALIZED: "panel-initialized",
 
-  initialize: Task.async(function*() {
+  initialize: Task.async(function* () {
     if (AnimationsController.destroyed) {
       console.warn("Could not initialize the animation-panel, controller " +
                    "was destroyed");
       return;
     }
     if (this.initialized) {
       yield this.initialized.promise;
       return;
@@ -74,17 +74,17 @@ var AnimationsPanel = {
     this.startListeners();
 
     yield this.refreshAnimationsUI();
 
     this.initialized.resolve();
     this.emit(this.PANEL_INITIALIZED);
   }),
 
-  destroy: Task.async(function*() {
+  destroy: Task.async(function* () {
     if (!this.initialized) {
       return;
     }
 
     if (this.destroyed) {
       yield this.destroyed.promise;
       return;
     }
@@ -200,17 +200,17 @@ var AnimationsPanel = {
   onToggleAllClicked: function() {
     this.toggleAll().catch(ex => console.error(ex));
   },
 
   /**
    * Toggle (pause/play) all animations in the current target
    * and update the UI the toggleAll button.
    */
-  toggleAll: Task.async(function*() {
+  toggleAll: Task.async(function* () {
     this.toggleAllButtonEl.classList.toggle("paused");
     yield AnimationsController.toggleAll();
   }),
 
   onTimelinePlayClicked: function() {
     this.playPauseTimeline().catch(ex => console.error(ex));
   },
 
@@ -275,44 +275,46 @@ var AnimationsPanel = {
     // If the timeline data changed as a result of the user dragging the
     // scrubber, then pause all animations and set their currentTimes.
     // (Note that we want server-side requests to be sequenced, so we only do
     // this after the previous currentTime setting was done).
     if (isUserDrag && !this.setCurrentTimeAllPromise) {
       this.setCurrentTimeAllPromise =
         AnimationsController.setCurrentTimeAll(time, true)
                             .catch(error => console.error(error))
-                            .then(() => this.setCurrentTimeAllPromise = null);
+                            .then(() => {
+                              this.setCurrentTimeAllPromise = null;
+                            });
     }
 
     this.displayTimelineCurrentTime();
   },
 
   displayTimelineCurrentTime: function() {
     let {time} = this.timelineData;
     this.timelineCurrentTimeEl.textContent = formatStopwatchTime(time);
   },
 
   /**
    * Make sure all known animations have their states up to date (which is
    * useful after the playState or currentTime has been changed and in case the
    * animations aren't auto-refreshing), and then refresh the UI.
    */
-  refreshAnimationsStateAndUI: Task.async(function*() {
+  refreshAnimationsStateAndUI: Task.async(function* () {
     for (let player of AnimationsController.animationPlayers) {
       yield player.refreshState();
     }
     yield this.refreshAnimationsUI();
   }),
 
   /**
    * Refresh the list of animations UI. This will empty the panel and re-render
    * the various components again.
    */
-  refreshAnimationsUI: Task.async(function*() {
+  refreshAnimationsUI: Task.async(function* () {
     // Empty the whole panel first.
     this.togglePlayers(true);
 
     // Re-render the timeline component.
     this.animationsTimelineComponent.render(
       AnimationsController.animationPlayers,
       AnimationsController.documentCurrentTime);
 

--- a/devtools/client/animationinspector/components/animation-details.js
+++ b/devtools/client/animationinspector/components/animation-details.js
@@ -57,17 +57,17 @@ AnimationDetails.prototype = {
     }
   },
 
   /**
    * Get a list of the tracks of the animation actor
    * @return {Object} A list of tracks, one per animated property, each
    * with a list of keyframes
    */
-  getTracks: Task.async(function*() {
+  getTracks: Task.async(function* () {
     let tracks = {};
 
     /*
      * getFrames is a AnimationPlayorActor method that returns data about the
      * keyframes of the animation.
      * In FF48, the data it returns change, and will hold only longhand
      * properties ( e.g. borderLeftWidth ), which does not match what we
      * want to display in the animation detail.
@@ -107,17 +107,17 @@ AnimationDetails.prototype = {
           });
         }
       }
     }
 
     return tracks;
   }),
 
-  render: Task.async(function*(animation) {
+  render: Task.async(function* (animation) {
     this.unrender();
 
     if (!animation) {
       return;
     }
     this.animation = animation;
 
     // We might have been destroyed in the meantime, or the component might

--- a/devtools/client/animationinspector/components/animation-target-node.js
+++ b/devtools/client/animationinspector/components/animation-target-node.js
@@ -36,17 +36,17 @@ AnimationTargetNode.prototype = {
   },
 
   destroy: function() {
     this.previewer.destroy();
     this.inspector = null;
     this.isDestroyed = true;
   },
 
-  render: Task.async(function*(playerFront) {
+  render: Task.async(function* (playerFront) {
     // Get the nodeFront from the cache if it was stored previously.
     let nodeFront = nodeFronts.get(playerFront);
 
     // Try and get it from the playerFront directly next.
     if (!nodeFront) {
       nodeFront = playerFront.animationTargetNodeFront;
     }
 

--- a/devtools/client/animationinspector/test/browser_animation_animated_properties_displayed.js
+++ b/devtools/client/animationinspector/test/browser_animation_animated_properties_displayed.js
@@ -16,17 +16,17 @@ const EXPECTED_PROPERTIES = [
   "border-top-left-radius",
   "border-top-right-radius",
   "filter",
   "height",
   "transform",
   "width"
 ].sort();
 
-add_task(function*() {
+add_task(function* () {
   yield addTab(URL_ROOT + "doc_keyframes.html");
   let {panel} = yield openAnimationInspector();
   let timeline = panel.animationsTimelineComponent;
   let propertiesList = timeline.rootWrapperEl
                                .querySelector(".animated-properties");
 
   ok(!isNodeVisible(propertiesList),
      "The list of properties panel is hidden by default");

--- a/devtools/client/animationinspector/test/browser_animation_click_selects_animation.js
+++ b/devtools/client/animationinspector/test/browser_animation_click_selects_animation.js
@@ -2,17 +2,17 @@
 /* Any copyright is dedicated to the Public Domain.
  http://creativecommons.org/publicdomain/zero/1.0/ */
 
 "use strict";
 
 // Check that animations displayed in the timeline can be selected by clicking
 // them, and that this emits the right events and adds the right classes.
 
-add_task(function*() {
+add_task(function* () {
   yield addTab(URL_ROOT + "doc_simple_animation.html");
   let {panel} = yield openAnimationInspector();
   let timeline = panel.animationsTimelineComponent;
 
   let selected = timeline.rootWrapperEl.querySelectorAll(".animation.selected");
   ok(!selected.length, "There are no animations selected by default");
 
   info("Click on the first animation, expect the right event and right class");

--- a/devtools/client/animationinspector/test/browser_animation_controller_exposes_document_currentTime.js
+++ b/devtools/client/animationinspector/test/browser_animation_controller_exposes_document_currentTime.js
@@ -2,17 +2,17 @@
 /* Any copyright is dedicated to the Public Domain.
  http://creativecommons.org/publicdomain/zero/1.0/ */
 
 "use strict";
 
 // Test that the controller provides the document.timeline currentTime (at least
 // the last known version since new animations were added).
 
-add_task(function*() {
+add_task(function* () {
   yield addTab(URL_ROOT + "doc_simple_animation.html");
   let {panel, controller} = yield openAnimationInspector();
 
   ok(controller.documentCurrentTime, "The documentCurrentTime getter exists");
   checkDocumentTimeIsCorrect(controller);
   let time1 = controller.documentCurrentTime;
 
   yield startNewAnimation(controller, panel);

--- a/devtools/client/animationinspector/test/browser_animation_empty_on_invalid_nodes.js
+++ b/devtools/client/animationinspector/test/browser_animation_empty_on_invalid_nodes.js
@@ -7,17 +7,17 @@ requestLongerTimeout(2);
 
 // Test that the panel shows no animation data for invalid or not animated nodes
 
 const { LocalizationHelper } = require("devtools/client/shared/l10n");
 
 const STRINGS_URI = "chrome://devtools/locale/animationinspector.properties";
 const L10N = new LocalizationHelper(STRINGS_URI);
 
-add_task(function*() {
+add_task(function* () {
   yield addTab(URL_ROOT + "doc_simple_animation.html");
   let {inspector, panel, window} = yield openAnimationInspector();
   let {document} = window;
 
   info("Select node .still and check that the panel is empty");
   let stillNode = yield getNodeFront(".still", inspector);
   let onUpdated = panel.once(panel.UI_UPDATED_EVENT);
   yield selectNodeAndWaitForAnimations(stillNode, inspector);

--- a/devtools/client/animationinspector/test/browser_animation_keyframe_click_to_set_time.js
+++ b/devtools/client/animationinspector/test/browser_animation_keyframe_click_to_set_time.js
@@ -2,17 +2,17 @@
 /* Any copyright is dedicated to the Public Domain.
  http://creativecommons.org/publicdomain/zero/1.0/ */
 
 "use strict";
 
 // Test that animated properties' keyframes can be clicked, and that doing so
 // sets the current time in the timeline.
 
-add_task(function*() {
+add_task(function* () {
   yield addTab(URL_ROOT + "doc_keyframes.html");
   let {panel} = yield openAnimationInspector();
   let timeline = panel.animationsTimelineComponent;
   let {scrubberEl} = timeline;
 
   // XXX: The scrollbar is placed in the timeline in such a way that it causes
   // the animations to be slightly offset with the header when it appears.
   // So for now, let's hide the scrollbar. Bug 1229340 should fix this.

--- a/devtools/client/animationinspector/test/browser_animation_keyframe_markers.js
+++ b/devtools/client/animationinspector/test/browser_animation_keyframe_markers.js
@@ -16,17 +16,17 @@ const EXPECTED_PROPERTIES = [
   "borderTopLeftRadius",
   "borderTopRightRadius",
   "filter",
   "height",
   "transform",
   "width"
 ];
 
-add_task(function*() {
+add_task(function* () {
   yield addTab(URL_ROOT + "doc_keyframes.html");
   let {panel} = yield openAnimationInspector();
   let timeline = panel.animationsTimelineComponent;
 
   info("Expand the animation");
   yield clickOnAnimation(panel, 0);
 
   ok(timeline.rootWrapperEl.querySelectorAll(".frames .keyframes").length,

--- a/devtools/client/animationinspector/test/browser_animation_mutations_with_same_names.js
+++ b/devtools/client/animationinspector/test/browser_animation_mutations_with_same_names.js
@@ -4,17 +4,17 @@
 
 "use strict";
 
 // Check that when animations are added later (through animation mutations) and
 // if these animations have the same names, then all of them are still being
 // displayed (which should be true as long as these animations apply to
 // different nodes).
 
-add_task(function*() {
+add_task(function* () {
   yield addTab(URL_ROOT + "doc_negative_animation.html");
   let {controller, panel} = yield openAnimationInspector();
 
   info("Wait until all animations have been added " +
        "(they're added with setTimeout)");
   while (controller.animationPlayers.length < 3) {
     yield controller.once(controller.PLAYERS_UPDATED_EVENT);
   }

--- a/devtools/client/animationinspector/test/browser_animation_panel_exists.js
+++ b/devtools/client/animationinspector/test/browser_animation_panel_exists.js
@@ -1,17 +1,17 @@
 /* vim: set ts=2 et sw=2 tw=80: */
 /* Any copyright is dedicated to the Public Domain.
  http://creativecommons.org/publicdomain/zero/1.0/ */
 
 "use strict";
 
 // Test that the animation panel sidebar exists
 
-add_task(function*() {
+add_task(function* () {
   yield addTab("data:text/html;charset=utf-8,welcome to the animation panel");
   let {panel, controller} = yield openAnimationInspector();
 
   ok(controller,
      "The animation controller exists");
   ok(controller.animationsFront,
      "The animation controller has been initialized");
   ok(panel,

--- a/devtools/client/animationinspector/test/browser_animation_participate_in_inspector_update.js
+++ b/devtools/client/animationinspector/test/browser_animation_participate_in_inspector_update.js
@@ -5,17 +5,17 @@
 "use strict";
 
 requestLongerTimeout(2);
 
 // Test that the update of the animation panel participate in the
 // inspector-updated event. This means that the test verifies that the
 // inspector-updated event is emitted *after* the animation panel is ready.
 
-add_task(function*() {
+add_task(function* () {
   yield addTab(URL_ROOT + "doc_simple_animation.html");
   let {inspector, panel, controller} = yield openAnimationInspector();
 
   info("Listen for the players-updated, ui-updated and " +
        "inspector-updated events");
   let receivedEvents = [];
   controller.once(controller.PLAYERS_UPDATED_EVENT, () => {
     receivedEvents.push(controller.PLAYERS_UPDATED_EVENT);

--- a/devtools/client/animationinspector/test/browser_animation_playerFronts_are_refreshed.js
+++ b/devtools/client/animationinspector/test/browser_animation_playerFronts_are_refreshed.js
@@ -4,17 +4,17 @@
 
 "use strict";
 
 requestLongerTimeout(2);
 
 // Check that the AnimationPlayerFront objects lifecycle is managed by the
 // AnimationController.
 
-add_task(function*() {
+add_task(function* () {
   yield addTab(URL_ROOT + "doc_simple_animation.html");
   let {controller, inspector} = yield openAnimationInspector();
 
   info("Selecting an animated node");
   // selectNode waits for the inspector-updated event before resolving, which
   // means the controller.PLAYERS_UPDATED_EVENT event has been emitted before
   // and players are ready.
   yield selectNodeAndWaitForAnimations(".animated", inspector);

--- a/devtools/client/animationinspector/test/browser_animation_playerWidgets_appear_on_panel_init.js
+++ b/devtools/client/animationinspector/test/browser_animation_playerWidgets_appear_on_panel_init.js
@@ -4,17 +4,17 @@
 
 "use strict";
 
 // Test that player widgets are displayed right when the animation panel is
 // initialized, if the selected node (<body> by default) is animated.
 
 const { ANIMATION_TYPES } = require("devtools/server/actors/animation");
 
-add_task(function*() {
+add_task(function* () {
   yield new Promise(resolve => {
     SpecialPowers.pushPrefEnv({"set": [
       ["dom.animations-api.core.enabled", true]
     ]}, resolve);
   });
 
   yield addTab(URL_ROOT + "doc_multiple_animation_types.html");
 

--- a/devtools/client/animationinspector/test/browser_animation_playerWidgets_target_nodes.js
+++ b/devtools/client/animationinspector/test/browser_animation_playerWidgets_target_nodes.js
@@ -3,17 +3,17 @@
  http://creativecommons.org/publicdomain/zero/1.0/ */
 
 "use strict";
 
 requestLongerTimeout(2);
 
 // Test that player widgets display information about target nodes
 
-add_task(function*() {
+add_task(function* () {
   yield addTab(URL_ROOT + "doc_simple_animation.html");
   let {inspector, panel} = yield openAnimationInspector();
 
   info("Select the simple animated node");
   yield selectNodeAndWaitForAnimations(".animated", inspector);
 
   let targetNodeComponent = panel.animationsTimelineComponent.targetNodes[0];
   let {previewer} = targetNodeComponent;

--- a/devtools/client/animationinspector/test/browser_animation_pseudo_elements.js
+++ b/devtools/client/animationinspector/test/browser_animation_pseudo_elements.js
@@ -1,17 +1,17 @@
 /* vim: set ts=2 et sw=2 tw=80: */
 /* Any copyright is dedicated to the Public Domain.
  http://creativecommons.org/publicdomain/zero/1.0/ */
 
 "use strict";
 
 // Test that animated pseudo-elements do show in the timeline.
 
-add_task(function*() {
+add_task(function* () {
   yield addTab(URL_ROOT + "doc_pseudo_elements.html");
   let {inspector, panel} = yield openAnimationInspector();
   let timeline = panel.animationsTimelineComponent;
 
   info("With <body> selected by default check the content of the timeline");
   is(timeline.timeBlocks.length, 3, "There are 3 animations in the timeline");
 
   let getTargetNodeText = index => {

--- a/devtools/client/animationinspector/test/browser_animation_refresh_on_added_animation.js
+++ b/devtools/client/animationinspector/test/browser_animation_refresh_on_added_animation.js
@@ -3,17 +3,17 @@
  http://creativecommons.org/publicdomain/zero/1.0/ */
 
 "use strict";
 
 requestLongerTimeout(2);
 
 // Test that the panel content refreshes when new animations are added.
 
-add_task(function*() {
+add_task(function* () {
   yield addTab(URL_ROOT + "doc_simple_animation.html");
   let {inspector, panel} = yield openAnimationInspector();
 
   info("Select a non animated node");
   yield selectNodeAndWaitForAnimations(".still", inspector);
 
   assertAnimationsDisplayed(panel, 0);
 

--- a/devtools/client/animationinspector/test/browser_animation_refresh_on_removed_animation.js
+++ b/devtools/client/animationinspector/test/browser_animation_refresh_on_removed_animation.js
@@ -3,17 +3,17 @@
  http://creativecommons.org/publicdomain/zero/1.0/ */
 
 "use strict";
 
 requestLongerTimeout(2);
 
 // Test that the panel content refreshes when animations are removed.
 
-add_task(function*() {
+add_task(function* () {
   yield addTab(URL_ROOT + "doc_simple_animation.html");
 
   let {inspector, panel} = yield openAnimationInspector();
   yield testRefreshOnRemove(inspector, panel);
 });
 
 function* testRefreshOnRemove(inspector, panel) {
   info("Select a animated node");

--- a/devtools/client/animationinspector/test/browser_animation_refresh_when_active.js
+++ b/devtools/client/animationinspector/test/browser_animation_refresh_when_active.js
@@ -3,17 +3,17 @@
  http://creativecommons.org/publicdomain/zero/1.0/ */
 
 "use strict";
 
 requestLongerTimeout(2);
 
 // Test that the panel only refreshes when it is visible in the sidebar.
 
-add_task(function*() {
+add_task(function* () {
   yield addTab(URL_ROOT + "doc_simple_animation.html");
 
   let {inspector, panel} = yield openAnimationInspector();
   yield testRefresh(inspector, panel);
 });
 
 function* testRefresh(inspector, panel) {
   info("Select a non animated node");

--- a/devtools/client/animationinspector/test/browser_animation_running_on_compositor.js
+++ b/devtools/client/animationinspector/test/browser_animation_running_on_compositor.js
@@ -9,17 +9,17 @@ requestLongerTimeout(2);
 // Test that when animations displayed in the timeline are running on the
 // compositor, they get a special icon and information in the tooltip.
 
 const { LocalizationHelper } = require("devtools/client/shared/l10n");
 
 const STRINGS_URI = "chrome://devtools/locale/animationinspector.properties";
 const L10N = new LocalizationHelper(STRINGS_URI);
 
-add_task(function*() {
+add_task(function* () {
   yield addTab(URL_ROOT + "doc_simple_animation.html");
   let {inspector, panel} = yield openAnimationInspector();
   let timeline = panel.animationsTimelineComponent;
 
   info("Select a test node we know has an animation running on the compositor");
   yield selectNodeAndWaitForAnimations(".animated", inspector);
 
   let animationEl = timeline.animationsEl.querySelector(".animation");

--- a/devtools/client/animationinspector/test/browser_animation_same_nb_of_playerWidgets_and_playerFronts.js
+++ b/devtools/client/animationinspector/test/browser_animation_same_nb_of_playerWidgets_and_playerFronts.js
@@ -4,17 +4,17 @@
 
 "use strict";
 
 requestLongerTimeout(2);
 
 // Check that when playerFronts are updated, the same number of playerWidgets
 // are created in the panel.
 
-add_task(function*() {
+add_task(function* () {
   yield addTab(URL_ROOT + "doc_simple_animation.html");
   let {inspector, panel, controller} = yield openAnimationInspector();
   let timeline = panel.animationsTimelineComponent;
 
   info("Selecting the test animated node again");
   yield selectNodeAndWaitForAnimations(".multi", inspector);
 
   is(controller.animationPlayers.length,

--- a/devtools/client/animationinspector/test/browser_animation_shows_player_on_valid_node.js
+++ b/devtools/client/animationinspector/test/browser_animation_shows_player_on_valid_node.js
@@ -4,17 +4,17 @@
 
 "use strict";
 
 requestLongerTimeout(2);
 
 // Test that the panel shows an animation player when an animated node is
 // selected.
 
-add_task(function*() {
+add_task(function* () {
   yield addTab(URL_ROOT + "doc_simple_animation.html");
   let {inspector, panel} = yield openAnimationInspector();
 
   info("Select node .animated and check that the panel is not empty");
   let node = yield getNodeFront(".animated", inspector);
   yield selectNodeAndWaitForAnimations(node, inspector);
 
   assertAnimationsDisplayed(panel, 1);

--- a/devtools/client/animationinspector/test/browser_animation_spacebar_toggles_animations.js
+++ b/devtools/client/animationinspector/test/browser_animation_spacebar_toggles_animations.js
@@ -5,17 +5,17 @@
 "use strict";
 
 // Test that the spacebar key press toggles the toggleAll button state
 // when a node with no animation is selected.
 // This test doesn't need to test if animations actually pause/resume
 // because there's an other test that does this :
 // browser_animation_toggle_button_toggles_animation.js
 
-add_task(function*() {
+add_task(function* () {
   yield addTab(URL_ROOT + "doc_simple_animation.html");
   let {panel, inspector, window, controller} = yield openAnimationInspector();
   let {toggleAllButtonEl} = panel;
 
   // select a node without animations
   yield selectNodeAndWaitForAnimations(".still", inspector);
 
   // ensure the focus is on the animation panel

--- a/devtools/client/animationinspector/test/browser_animation_spacebar_toggles_node_animations.js
+++ b/devtools/client/animationinspector/test/browser_animation_spacebar_toggles_node_animations.js
@@ -5,17 +5,17 @@
 "use strict";
 
 // Test that the spacebar key press toggles the play/resume button state.
 // This test doesn't need to test if animations actually pause/resume
 // because there's an other test that does this.
 // There are animations in the test page and since, by default, the <body> node
 // is selected, animations will be displayed in the timeline, so the timeline
 // play/resume button will be displayed
-add_task(function*() {
+add_task(function* () {
   yield addTab(URL_ROOT + "doc_simple_animation.html");
   let {panel, window} = yield openAnimationInspector();
   let {playTimelineButtonEl} = panel;
 
   // ensure the focus is on the animation panel
   window.focus();
 
   info("Simulate spacebar stroke and check playResume button" +

--- a/devtools/client/animationinspector/test/browser_animation_target_highlight_select.js
+++ b/devtools/client/animationinspector/test/browser_animation_target_highlight_select.js
@@ -4,17 +4,17 @@
 
 "use strict";
 
 requestLongerTimeout(2);
 
 // Test that the DOM element targets displayed in animation player widgets can
 // be used to highlight elements in the DOM and select them in the inspector.
 
-add_task(function*() {
+add_task(function* () {
   yield addTab(URL_ROOT + "doc_simple_animation.html");
 
   let {toolbox, inspector, panel} = yield openAnimationInspector();
 
   info("Select the simple animated node");
   let onPanelUpdated = panel.once(panel.UI_UPDATED_EVENT);
   yield selectNodeAndWaitForAnimations(".animated", inspector);
   yield onPanelUpdated;

--- a/devtools/client/animationinspector/test/browser_animation_target_highlighter_lock.js
+++ b/devtools/client/animationinspector/test/browser_animation_target_highlighter_lock.js
@@ -4,17 +4,17 @@
 
 "use strict";
 
 requestLongerTimeout(2);
 
 // Test that the DOM element targets displayed in animation player widgets can
 // be used to highlight elements in the DOM and select them in the inspector.
 
-add_task(function*() {
+add_task(function* () {
   yield addTab(URL_ROOT + "doc_simple_animation.html");
   let {panel} = yield openAnimationInspector();
 
   let targets = panel.animationsTimelineComponent.targetNodes;
 
   info("Click on the highlighter icon for the first animated node");
   let domNodePreview1 = targets[0].previewer;
   yield lockHighlighterOn(domNodePreview1);

--- a/devtools/client/animationinspector/test/browser_animation_timeline_currentTime.js
+++ b/devtools/client/animationinspector/test/browser_animation_timeline_currentTime.js
@@ -5,17 +5,17 @@
 "use strict";
 
 requestLongerTimeout(2);
 
 // Check that the timeline toolbar displays the current time, and that it
 // changes when animations are playing, gets back to 0 when animations are
 // rewound, and stops when animations are paused.
 
-add_task(function*() {
+add_task(function* () {
   yield addTab(URL_ROOT + "doc_simple_animation.html");
 
   let {panel} = yield openAnimationInspector();
   let label = panel.timelineCurrentTimeEl;
   ok(label, "The current time label exists");
 
   // On page load animations are playing so the time shoud change, although we
   // don't want to test the exact value of the time displayed, just that it

--- a/devtools/client/animationinspector/test/browser_animation_timeline_header.js
+++ b/devtools/client/animationinspector/test/browser_animation_timeline_header.js
@@ -9,17 +9,17 @@ requestLongerTimeout(2);
 // Check that the timeline shows correct time graduations in the header.
 
 const {findOptimalTimeInterval, TimeScale} = require("devtools/client/animationinspector/utils");
 
 // Should be kept in sync with TIME_GRADUATION_MIN_SPACING in
 // animation-timeline.js
 const TIME_GRADUATION_MIN_SPACING = 40;
 
-add_task(function*() {
+add_task(function* () {
   yield addTab(URL_ROOT + "doc_simple_animation.html");
   let {panel} = yield openAnimationInspector();
 
   let timeline = panel.animationsTimelineComponent;
   let headerEl = timeline.timeHeaderEl;
 
   info("Find out how many time graduations should there be");
   let width = headerEl.offsetWidth;

--- a/devtools/client/animationinspector/test/browser_animation_timeline_iterationStart.js
+++ b/devtools/client/animationinspector/test/browser_animation_timeline_iterationStart.js
@@ -1,17 +1,17 @@
 /* vim: set ts=2 et sw=2 tw=80: */
 /* Any copyright is dedicated to the Public Domain.
  http://creativecommons.org/publicdomain/zero/1.0/ */
 
 "use strict";
 
 // Check that the iteration start is displayed correctly in time blocks.
 
-add_task(function*() {
+add_task(function* () {
   yield addTab(URL_ROOT + "doc_script_animation.html");
   let {panel} = yield openAnimationInspector();
   let timelineComponent = panel.animationsTimelineComponent;
   let timeBlockComponents = timelineComponent.timeBlocks;
   let detailsComponents = timelineComponent.details;
 
   for (let i = 0; i < timeBlockComponents.length; i++) {
     info(`Expand time block ${i} so its keyframes are visible`);

--- a/devtools/client/animationinspector/test/browser_animation_timeline_pause_button.js
+++ b/devtools/client/animationinspector/test/browser_animation_timeline_pause_button.js
@@ -11,17 +11,17 @@ requestLongerTimeout(2);
 // displayed in the timeline get their playstates changed accordingly, and check
 // that the scrubber resumes/stops moving.
 // Also checks that the button goes to the right state when the scrubber has
 // reached the end of the timeline: continues to be in playing mode for infinite
 // animations, goes to paused mode otherwise.
 // And test that clicking the button once the scrubber has reached the end of
 // the timeline does the right thing.
 
-add_task(function*() {
+add_task(function* () {
   yield addTab(URL_ROOT + "doc_simple_animation.html");
 
   let {panel, inspector} = yield openAnimationInspector();
   let timeline = panel.animationsTimelineComponent;
   let btn = panel.playTimelineButtonEl;
 
   ok(btn, "The play/pause button exists");
   ok(!btn.classList.contains("paused"),

--- a/devtools/client/animationinspector/test/browser_animation_timeline_rate_selector.js
+++ b/devtools/client/animationinspector/test/browser_animation_timeline_rate_selector.js
@@ -7,17 +7,17 @@
 requestLongerTimeout(2);
 
 // Check that the timeline toolbar contains a playback rate selector UI and that
 // it can be used to change the playback rate of animations in the timeline.
 // Also check that it displays the rate of the current animations in case they
 // all have the same rate, or that it displays the empty value in case they
 // have mixed rates.
 
-add_task(function*() {
+add_task(function* () {
   yield addTab(URL_ROOT + "doc_simple_animation.html");
 
   let {panel, controller, inspector, toolbox} = yield openAnimationInspector();
 
   // In this test, we disable the highlighter on purpose because of the way
   // events are simulated to select an option in the playbackRate <select>.
   // Indeed, this may cause mousemove events to be triggered on the nodes that
   // are underneath the <select>, and these are AnimationTargetNode instances.

--- a/devtools/client/animationinspector/test/browser_animation_timeline_rewind_button.js
+++ b/devtools/client/animationinspector/test/browser_animation_timeline_rewind_button.js
@@ -7,17 +7,17 @@
 requestLongerTimeout(2);
 
 // Check that the timeline toolbar contains a rewind button and that it can be
 // clicked. Check that when it is, the current animations displayed in the
 // timeline get their playstates changed to paused, and their currentTimes
 // reset to 0, and that the scrubber stops moving and is positioned to the
 // start.
 
-add_task(function*() {
+add_task(function* () {
   yield addTab(URL_ROOT + "doc_simple_animation.html");
 
   let {panel, controller} = yield openAnimationInspector();
   let players = controller.animationPlayers;
   let btn = panel.rewindTimelineButtonEl;
 
   ok(btn, "The rewind button exists");
 

--- a/devtools/client/animationinspector/test/browser_animation_timeline_scrubber_exists.js
+++ b/devtools/client/animationinspector/test/browser_animation_timeline_scrubber_exists.js
@@ -3,17 +3,17 @@
  http://creativecommons.org/publicdomain/zero/1.0/ */
 
 "use strict";
 
 requestLongerTimeout(2);
 
 // Check that the timeline does have a scrubber element.
 
-add_task(function*() {
+add_task(function* () {
   yield addTab(URL_ROOT + "doc_simple_animation.html");
   let {panel} = yield openAnimationInspector();
 
   let timeline = panel.animationsTimelineComponent;
   let scrubberEl = timeline.scrubberEl;
 
   ok(scrubberEl, "The scrubber element exists");
   ok(scrubberEl.classList.contains("scrubber"), "It has the right classname");

--- a/devtools/client/animationinspector/test/browser_animation_timeline_scrubber_movable.js
+++ b/devtools/client/animationinspector/test/browser_animation_timeline_scrubber_movable.js
@@ -7,17 +7,17 @@
 requestLongerTimeout(2);
 
 // Check that the scrubber in the timeline can be moved by clicking & dragging
 // in the header area.
 // Also check that doing so changes the timeline's play/pause button to paused
 // state.
 // Finally, also check that the scrubber can be moved using the scrubber handle.
 
-add_task(function*() {
+add_task(function* () {
   yield addTab(URL_ROOT + "doc_simple_animation.html");
 
   let {panel} = yield openAnimationInspector();
   let timeline = panel.animationsTimelineComponent;
   let {win, timeHeaderEl, scrubberEl, scrubberHandleEl} = timeline;
   let playTimelineButtonEl = panel.playTimelineButtonEl;
 
   ok(!playTimelineButtonEl.classList.contains("paused"),

--- a/devtools/client/animationinspector/test/browser_animation_timeline_scrubber_moves.js
+++ b/devtools/client/animationinspector/test/browser_animation_timeline_scrubber_moves.js
@@ -6,17 +6,17 @@
 
 requestLongerTimeout(2);
 
 // Check that the scrubber in the timeline moves when animations are playing.
 // The animations in the test page last for a very long time, so the test just
 // measures the position of the scrubber once, then waits for some time to pass
 // and measures its position again.
 
-add_task(function*() {
+add_task(function* () {
   yield addTab(URL_ROOT + "doc_simple_animation.html");
   let {panel} = yield openAnimationInspector();
 
   let timeline = panel.animationsTimelineComponent;
   let scrubberEl = timeline.scrubberEl;
   let startPos = scrubberEl.getBoundingClientRect().left;
 
   info("Wait for some time to check that the scrubber moves");

--- a/devtools/client/animationinspector/test/browser_animation_timeline_shows_delay.js
+++ b/devtools/client/animationinspector/test/browser_animation_timeline_shows_delay.js
@@ -6,17 +6,17 @@
 
 requestLongerTimeout(2);
 
 // Check that animation delay is visualized in the timeline when the animation
 // is delayed.
 // Also check that negative delays do not overflow the UI, and are shown like
 // positive delays.
 
-add_task(function*() {
+add_task(function* () {
   yield addTab(URL_ROOT + "doc_simple_animation.html");
   let {inspector, panel} = yield openAnimationInspector();
 
   info("Selecting a delayed animated node");
   yield selectNodeAndWaitForAnimations(".delayed", inspector);
   let timelineEl = panel.animationsTimelineComponent.rootWrapperEl;
   checkDelayAndName(timelineEl, true);
 

--- a/devtools/client/animationinspector/test/browser_animation_timeline_shows_endDelay.js
+++ b/devtools/client/animationinspector/test/browser_animation_timeline_shows_endDelay.js
@@ -6,17 +6,17 @@
 
 requestLongerTimeout(2);
 
 // Check that animation endDelay is visualized in the timeline when the
 // animation is delayed.
 // Also check that negative endDelays do not overflow the UI, and are shown
 // like positive endDelays.
 
-add_task(function*() {
+add_task(function* () {
   yield addTab(URL_ROOT + "doc_end_delay.html");
   let {inspector, panel} = yield openAnimationInspector();
 
   let selectors = ["#target1", "#target2", "#target3", "#target4"];
   for (let i = 0; i < selectors.length; i++) {
     let selector = selectors[i];
     yield selectNode(selector, inspector);
     let timelineEl = panel.animationsTimelineComponent.rootWrapperEl;

--- a/devtools/client/animationinspector/test/browser_animation_timeline_shows_iterations.js
+++ b/devtools/client/animationinspector/test/browser_animation_timeline_shows_iterations.js
@@ -4,17 +4,17 @@
 
 "use strict";
 
 requestLongerTimeout(2);
 
 // Check that the timeline is displays as many iteration elements as there are
 // iterations in an animation.
 
-add_task(function*() {
+add_task(function* () {
   yield addTab(URL_ROOT + "doc_simple_animation.html");
   let {inspector, panel} = yield openAnimationInspector();
 
   info("Selecting the test node");
   yield selectNodeAndWaitForAnimations(".delayed", inspector);
 
   info("Getting the animation element from the panel");
   let timelineEl = panel.animationsTimelineComponent.rootWrapperEl;

--- a/devtools/client/animationinspector/test/browser_animation_timeline_shows_time_info.js
+++ b/devtools/client/animationinspector/test/browser_animation_timeline_shows_time_info.js
@@ -4,17 +4,17 @@
 
 "use strict";
 
 requestLongerTimeout(2);
 
 // Check that the timeline displays animations' duration, delay iteration
 // counts and iteration start in tooltips.
 
-add_task(function*() {
+add_task(function* () {
   yield addTab(URL_ROOT + "doc_simple_animation.html");
   let {panel, controller} = yield openAnimationInspector();
 
   info("Getting the animation element from the panel");
   let timelineEl = panel.animationsTimelineComponent.rootWrapperEl;
   let timeBlockNameEls = timelineEl.querySelectorAll(".time-block .name");
 
   // Verify that each time-block's name element has a tooltip that looks sort of

--- a/devtools/client/animationinspector/test/browser_animation_timeline_takes_rate_into_account.js
+++ b/devtools/client/animationinspector/test/browser_animation_timeline_takes_rate_into_account.js
@@ -6,17 +6,17 @@
 
 // Check that if an animation has had its playbackRate changed via the DOM, then
 // the timeline UI shows the right delay and duration.
 // Indeed, the header in the timeline UI always shows the unaltered time,
 // because there might be multiple animations displayed at the same time, some
 // of which may have a different rate than others. Those that have had their
 // rate changed have a delay = delay/rate and a duration = duration/rate.
 
-add_task(function*() {
+add_task(function* () {
   yield new Promise(resolve => {
     SpecialPowers.pushPrefEnv({"set": [
       ["dom.animations-api.core.enabled", true]
     ]}, resolve);
   });
 
   yield addTab(URL_ROOT + "doc_modify_playbackRate.html");
 

--- a/devtools/client/animationinspector/test/browser_animation_timeline_ui.js
+++ b/devtools/client/animationinspector/test/browser_animation_timeline_ui.js
@@ -3,17 +3,17 @@
  http://creativecommons.org/publicdomain/zero/1.0/ */
 
 "use strict";
 
 requestLongerTimeout(2);
 
 // Check that the timeline contains the right elements.
 
-add_task(function*() {
+add_task(function* () {
   yield addTab(URL_ROOT + "doc_simple_animation.html");
   let {panel} = yield openAnimationInspector();
 
   let timeline = panel.animationsTimelineComponent;
   let el = timeline.rootWrapperEl;
 
   ok(el.querySelector(".time-header"),
      "The header element is in the DOM of the timeline");

--- a/devtools/client/animationinspector/test/browser_animation_toggle_button_resets_on_navigate.js
+++ b/devtools/client/animationinspector/test/browser_animation_toggle_button_resets_on_navigate.js
@@ -3,17 +3,17 @@
  http://creativecommons.org/publicdomain/zero/1.0/ */
 
 "use strict";
 
 requestLongerTimeout(2);
 
 // Test that a page navigation resets the state of the global toggle button.
 
-add_task(function*() {
+add_task(function* () {
   yield addTab(URL_ROOT + "doc_simple_animation.html");
   let {inspector, panel} = yield openAnimationInspector();
 
   info("Select the non-animated test node");
   yield selectNodeAndWaitForAnimations(".still", inspector);
 
   ok(!panel.toggleAllButtonEl.classList.contains("paused"),
     "The toggle button is in its running state by default");

--- a/devtools/client/animationinspector/test/browser_animation_toggle_button_toggles_animations.js
+++ b/devtools/client/animationinspector/test/browser_animation_toggle_button_toggles_animations.js
@@ -6,17 +6,17 @@
 
 requestLongerTimeout(2);
 
 // Test that the main toggle button actually toggles animations.
 // This test doesn't need to be extra careful about checking that *all*
 // animations have been paused (including inside iframes) because there's an
 // actor test in /devtools/server/tests/browser/ that does this.
 
-add_task(function*() {
+add_task(function* () {
   yield addTab(URL_ROOT + "doc_simple_animation.html");
   let {panel} = yield openAnimationInspector();
 
   info("Click the toggle button");
   yield panel.toggleAll();
   yield checkState("paused");
 
   info("Click again the toggle button");

--- a/devtools/client/animationinspector/test/browser_animation_toolbar_exists.js
+++ b/devtools/client/animationinspector/test/browser_animation_toolbar_exists.js
@@ -6,17 +6,17 @@
 
 requestLongerTimeout(2);
 
 // Test that the animation panel has a top toolbar that contains the play/pause
 // button and that is displayed at all times.
 // Also test that this toolbar gets replaced by the timeline toolbar when there
 // are animations to be displayed.
 
-add_task(function*() {
+add_task(function* () {
   yield addTab(URL_ROOT + "doc_simple_animation.html");
   let {inspector, window} = yield openAnimationInspector();
   let doc = window.document;
   let toolbar = doc.querySelector("#global-toolbar");
 
   ok(toolbar, "The panel contains the toolbar element with the new UI");
   ok(!isNodeVisible(toolbar),
      "The toolbar is hidden while there are animations");

--- a/devtools/client/animationinspector/test/browser_animation_ui_updates_when_animation_data_changes.js
+++ b/devtools/client/animationinspector/test/browser_animation_ui_updates_when_animation_data_changes.js
@@ -4,17 +4,17 @@
 
 "use strict";
 
 requestLongerTimeout(2);
 
 // Verify that if the animation's duration, iterations or delay change in
 // content, then the widget reflects the changes.
 
-add_task(function*() {
+add_task(function* () {
   yield addTab(URL_ROOT + "doc_simple_animation.html");
   let {panel, controller, inspector} = yield openAnimationInspector();
 
   info("Select the test node");
   yield selectNodeAndWaitForAnimations(".animated", inspector);
 
   let animation = controller.animationPlayers[0];
   yield setStyle(animation, panel, "animationDuration", "5.5s");

--- a/devtools/client/animationinspector/test/head.js
+++ b/devtools/client/animationinspector/test/head.js
@@ -12,17 +12,17 @@ Services.scriptloader.loadSubScript(
   this);
 
 const {ViewHelpers} = Cu.import("resource://devtools/client/shared/widgets/ViewHelpers.jsm", {});
 const FRAME_SCRIPT_URL = CHROME_URL_ROOT + "doc_frame_script.js";
 const COMMON_FRAME_SCRIPT_URL = "chrome://devtools/content/shared/frame-script-utils.js";
 const TAB_NAME = "animationinspector";
 
 // Auto clean-up when a test ends
-registerCleanupFunction(function*() {
+registerCleanupFunction(function* () {
   yield closeAnimationInspector();
 
   while (gBrowser.tabs.length > 1) {
     gBrowser.removeCurrentTab();
   }
 });
 
 // Clean-up all prefs that might have been changed during a test run
@@ -70,17 +70,17 @@ function* reloadTab(inspector) {
  * loaded in the toolbox
  * @param {String} reason
  *        Defaults to "test" which instructs the inspector not
  *        to highlight the node upon selection
  * @return {Promise} Resolves when the inspector is updated with the new node
            and animations of its subtree are properly displayed.
  */
 var selectNodeAndWaitForAnimations = Task.async(
-  function*(data, inspector, reason = "test") {
+  function* (data, inspector, reason = "test") {
     yield selectNode(data, inspector, reason);
 
     // We want to make sure the rest of the test waits for the animations to
     // be properly displayed (wait for all target DOM nodes to be previewed).
     let {AnimationsPanel} = inspector.sidebar.getWindowForTab(TAB_NAME);
     yield waitForAllAnimationTargets(AnimationsPanel);
   }
 );
@@ -102,17 +102,17 @@ function assertAnimationsDisplayed(panel
 /**
  * Takes an Inspector panel that was just created, and waits
  * for a "inspector-updated" event as well as the animation inspector
  * sidebar to be ready. Returns a promise once these are completed.
  *
  * @param {InspectorPanel} inspector
  * @return {Promise}
  */
-var waitForAnimationInspectorReady = Task.async(function*(inspector) {
+var waitForAnimationInspectorReady = Task.async(function* (inspector) {
   let win = inspector.sidebar.getWindowForTab(TAB_NAME);
   let updated = inspector.once("inspector-updated");
 
   // In e10s, if we wait for underlying toolbox actors to
   // load (by setting DevToolsUtils.testing to true), we miss the
   // "animationinspector-ready" event on the sidebar, so check to see if the
   // iframe is already loaded.
   let tabReady = win.document.readyState === "complete" ?
@@ -122,17 +122,17 @@ var waitForAnimationInspectorReady = Tas
   return promise.all([updated, tabReady]);
 });
 
 /**
  * Open the toolbox, with the inspector tool visible and the animationinspector
  * sidebar selected.
  * @return a promise that resolves when the inspector is ready.
  */
-var openAnimationInspector = Task.async(function*() {
+var openAnimationInspector = Task.async(function* () {
   let {inspector, toolbox} = yield openInspectorSidebarTab(TAB_NAME);
 
   info("Waiting for the inspector and sidebar to be ready");
   yield waitForAnimationInspectorReady(inspector);
 
   let win = inspector.sidebar.getWindowForTab(TAB_NAME);
   let {AnimationsController, AnimationsPanel} = win;
 
@@ -156,17 +156,17 @@ var openAnimationInspector = Task.async(
     window: win
   };
 });
 
 /**
  * Close the toolbox.
  * @return a promise that resolves when the toolbox has closed.
  */
-var closeAnimationInspector = Task.async(function*() {
+var closeAnimationInspector = Task.async(function* () {
   let target = TargetFactory.forTab(gBrowser.selectedTab);
   yield gDevTools.closeToolbox(target);
 });
 
 /**
  * Wait for a content -> chrome message on the message manager (the window
  * messagemanager is used).
  * @param {String} name The message name
@@ -209,18 +209,18 @@ function executeInContent(name, data = {
   }
 
   return promise.resolve();
 }
 
 /**
  * Get the current playState of an animation player on a given node.
  */
-var getAnimationPlayerState = Task.async(function*(selector,
-                                                   animationIndex = 0) {
+var getAnimationPlayerState = Task.async(function* (selector,
+                                                    animationIndex = 0) {
   let playState = yield executeInContent("Test:GetAnimationPlayerState",
                                          {selector, animationIndex});
   return playState;
 });
 
 /**
  * Is the given node visible in the page (rendered in the frame tree).
  * @param {DOMNode}
@@ -231,17 +231,17 @@ function isNodeVisible(node) {
 }
 
 /**
  * Wait for all AnimationTargetNode instances to be fully loaded
  * (fetched their related actor and rendered), and return them.
  * @param {AnimationsPanel} panel
  * @return {Array} all AnimationTargetNode instances
  */
-var waitForAllAnimationTargets = Task.async(function*(panel) {
+var waitForAllAnimationTargets = Task.async(function* (panel) {
   let targets = panel.animationsTimelineComponent.targetNodes;
   yield promise.all(targets.map(t => {
     if (!t.previewer.nodeFront) {
       return t.once("target-retrieved");
     }
     return false;
   }));
   return targets;
@@ -260,17 +260,19 @@ function* assertScrubberMoving(panel, is
     // timeline-data-changed events and compare times.
     let {time: time1} = yield timeline.once("timeline-data-changed");
     let {time: time2} = yield timeline.once("timeline-data-changed");
     ok(time2 > time1, "The scrubber is moving");
   } else {
     // If instead we expect the scrubber to remain at its position, just wait
     // for some time and make sure timeline-data-changed isn't emitted.
     let hasMoved = false;
-    timeline.once("timeline-data-changed", () => hasMoved = true);
+    timeline.once("timeline-data-changed", () => {
+      hasMoved = true;
+    });
     yield new Promise(r => setTimeout(r, 500));
     ok(!hasMoved, "The scrubber is not moving");
   }
 }
 
 /**
  * Click the play/pause button in the timeline toolbar and wait for animations
  * to update.

--- a/devtools/client/definitions.js
+++ b/devtools/client/definitions.js
@@ -136,16 +136,17 @@ Tools.webConsole = {
 
   preventClosingOnKey: true,
   onkey: function(panel, toolbox) {
     if (toolbox.splitConsole) {
       return toolbox.focusConsoleInput();
     }
 
     panel.focusInput();
+    return undefined;
   },
 
   isTargetSupported: function() {
     return true;
   },
 
   build: function(iframeWindow, toolbox) {
     return new WebConsolePanel(iframeWindow, toolbox);

--- a/devtools/client/inspector/layout/layout.js
+++ b/devtools/client/inspector/layout/layout.js
@@ -599,16 +599,17 @@ LayoutView.prototype = {
       let newValue = width + "\u00D7" + height;
       if (this.sizeLabel.textContent != newValue) {
         this.sizeLabel.textContent = newValue;
       }
 
       this.elementRules = styleEntries.map(e => e.rule);
 
       this.inspector.emit("layoutview-updated");
+      return undefined;
     }).bind(this)).catch(console.error);
 
     this._lastRequest = lastRequest;
     return this._lastRequest;
   },
 
   /**
    * Update the text in the tooltip shown when hovering over a value to provide

--- a/devtools/client/inspector/layout/test/browser_layout.js
+++ b/devtools/client/inspector/layout/test/browser_layout.js
@@ -121,17 +121,17 @@ var res2 = [
     value: 10
   },
   {
     selector: ".layout-border.layout-right > span",
     value: 10
   },
 ];
 
-add_task(function*() {
+add_task(function* () {
   let style = "div { position: absolute; top: 42px; left: 42px; " +
               "height: 100.111px; width: 100px; border: 10px solid black; " +
               "padding: 20px; margin: 30px auto;}";
   let html = "<style>" + style + "</style><div></div>";
 
   yield addTab("data:text/html," + encodeURIComponent(html));
   let {inspector, view, testActor} = yield openLayoutView();
   yield selectNode("div", inspector);

--- a/devtools/client/inspector/layout/test/browser_layout_editablemodel.js
+++ b/devtools/client/inspector/layout/test/browser_layout_editablemodel.js
@@ -14,17 +14,17 @@ const TEST_URI = "<style>" +
   "#div3 { padding: 2em; }" +
   "#div4 { margin: 1px; }" +
   "#div5 { margin: 1px; }" +
   "</style>" +
   "<div id='div1'></div><div id='div2'></div>" +
   "<div id='div3'></div><div id='div4'></div>" +
   "<div id='div5'></div>";
 
-add_task(function*() {
+add_task(function* () {
   yield addTab("data:text/html," + encodeURIComponent(TEST_URI));
   let {inspector, view, testActor} = yield openLayoutView();
 
   yield testEditingMargins(inspector, view, testActor);
   yield testKeyBindings(inspector, view, testActor);
   yield testEscapeToUndo(inspector, view, testActor);
   yield testDeletingValue(inspector, view, testActor);
   yield testRefocusingOnClick(inspector, view, testActor);

--- a/devtools/client/inspector/layout/test/browser_layout_editablemodel_allproperties.js
+++ b/devtools/client/inspector/layout/test/browser_layout_editablemodel_allproperties.js
@@ -9,17 +9,17 @@
 const TEST_URI = "<style>" +
   "div { margin: 10px; padding: 3px }" +
   "#div1 { margin-top: 5px }" +
   "#div2 { border-bottom: 1em solid black; }" +
   "#div3 { padding: 2em; }" +
   "</style>" +
   "<div id='div1'></div><div id='div2'></div><div id='div3'></div>";
 
-add_task(function*() {
+add_task(function* () {
   yield addTab("data:text/html," + encodeURIComponent(TEST_URI));
   let {inspector, view, testActor} = yield openLayoutView();
 
   yield testEditing(inspector, view, testActor);
   yield testEditingAndCanceling(inspector, view, testActor);
   yield testDeleting(inspector, view, testActor);
   yield testDeletingAndCanceling(inspector, view, testActor);
 });

--- a/devtools/client/inspector/layout/test/browser_layout_editablemodel_border.js
+++ b/devtools/client/inspector/layout/test/browser_layout_editablemodel_border.js
@@ -9,17 +9,17 @@
 const TEST_URI = "<style>" +
   "div { margin: 10px; padding: 3px }" +
   "#div1 { margin-top: 5px }" +
   "#div2 { border-bottom: 1em solid black; }" +
   "#div3 { padding: 2em; }" +
   "</style>" +
   "<div id='div1'></div><div id='div2'></div><div id='div3'></div>";
 
-add_task(function*() {
+add_task(function* () {
   yield addTab("data:text/html," + encodeURIComponent(TEST_URI));
   let {inspector, view, testActor} = yield openLayoutView();
 
   is((yield getStyle(testActor, "#div1", "border-top-width")), "",
      "Should have the right border");
   is((yield getStyle(testActor, "#div1", "border-top-style")), "",
      "Should have the right border");
   yield selectNode("#div1", inspector);

--- a/devtools/client/inspector/layout/test/browser_layout_editablemodel_stylerules.js
+++ b/devtools/client/inspector/layout/test/browser_layout_editablemodel_stylerules.js
@@ -10,17 +10,17 @@
 const TEST_URI = "<style>" +
   "div { margin: 10px; padding: 3px }" +
   "#div1 { margin-top: 5px }" +
   "#div2 { border-bottom: 1em solid black; }" +
   "#div3 { padding: 2em; }" +
   "</style>" +
   "<div id='div1'></div><div id='div2'></div><div id='div3'></div>";
 
-add_task(function*() {
+add_task(function* () {
   yield addTab("data:text/html," + encodeURIComponent(TEST_URI));
   let {inspector, view, testActor} = yield openLayoutView();
 
   yield testUnits(inspector, view, testActor);
   yield testValueComesFromStyleRule(inspector, view, testActor);
   yield testShorthandsAreParsed(inspector, view, testActor);
 });
 

--- a/devtools/client/inspector/layout/test/browser_layout_guides.js
+++ b/devtools/client/inspector/layout/test/browser_layout_guides.js
@@ -12,17 +12,17 @@
 const STYLE = "div { position: absolute; top: 50px; left: 50px; " +
               "height: 10px; width: 10px; border: 10px solid black; " +
               "padding: 10px; margin: 10px;}";
 const HTML = "<style>" + STYLE + "</style><div></div>";
 const TEST_URL = "data:text/html;charset=utf-8," + encodeURIComponent(HTML);
 
 var highlightedNodeFront, highlighterOptions;
 
-add_task(function*() {
+add_task(function* () {
   yield addTab(TEST_URL);
   let {toolbox, inspector, view} = yield openLayoutView();
   yield selectNode("div", inspector);
 
   // Mock the highlighter by replacing the showBoxModel method.
   toolbox.highlighter.showBoxModel = function(nodeFront, options) {
     highlightedNodeFront = nodeFront;
     highlighterOptions = options;

--- a/devtools/client/inspector/layout/test/browser_layout_rotate-labels-on-sides.js
+++ b/devtools/client/inspector/layout/test/browser_layout_rotate-labels-on-sides.js
@@ -25,17 +25,17 @@ const TEST_URI = encodeURIComponent([
   "<style>",
   "div { border:10px solid black; padding: 20px 20px 20px 2000000px; " +
   "margin: 30px auto; }",
   "</style>",
   "<div></div>"
 ].join(""));
 const LONG_TEXT_ROTATE_LIMIT = 3;
 
-add_task(function*() {
+add_task(function* () {
   yield addTab("data:text/html," + TEST_URI);
   let {inspector, view} = yield openLayoutView();
   yield selectNode("div", inspector);
 
   for (let i = 0; i < res1.length; i++) {
     let elt = view.doc.querySelector(res1[i].selector);
     let isLong = elt.textContent.length > LONG_TEXT_ROTATE_LIMIT;
     let classList = elt.parentNode.classList;

--- a/devtools/client/inspector/layout/test/browser_layout_tooltips.js
+++ b/devtools/client/inspector/layout/test/browser_layout_tooltips.js
@@ -65,17 +65,17 @@ const VALUES_TEST_DATA = [{
     styleSheetLocation: "null:3"
   }, {
     name: "padding-left",
     ruleSelector: "html, body, #div3",
     styleSheetLocation: "null:3"
   }]
 }];
 
-add_task(function*() {
+add_task(function* () {
   yield addTab("data:text/html;charset=utf-8," + encodeURIComponent(TEST_URI));
   let {inspector, view} = yield openLayoutView();
 
   info("Checking the regions tooltips");
 
   ok(view.doc.querySelector("#layout-margins").hasAttribute("title"),
     "The margin region has a tooltip");
   is(view.doc.querySelector("#layout-margins").getAttribute("title"), "margin",

--- a/devtools/client/inspector/layout/test/browser_layout_update-after-navigation.js
+++ b/devtools/client/inspector/layout/test/browser_layout_update-after-navigation.js
@@ -5,17 +5,17 @@
 "use strict";
 
 // Test that the layout-view continues to work after a page navigation and that
 // it also works after going back
 
 const IFRAME1 = URL_ROOT + "doc_layout_iframe1.html";
 const IFRAME2 = URL_ROOT + "doc_layout_iframe2.html";
 
-add_task(function*() {
+add_task(function* () {
   yield addTab(IFRAME1);
   let {inspector, view, testActor} = yield openLayoutView();
 
   yield testFirstPage(inspector, view, testActor);
 
   info("Navigate to the second page");
   yield testActor.eval(`content.location.href="${IFRAME2}"`);
   yield inspector.once("markuploaded");

--- a/devtools/client/inspector/layout/test/browser_layout_update-after-reload.js
+++ b/devtools/client/inspector/layout/test/browser_layout_update-after-reload.js
@@ -1,17 +1,17 @@
 /* vim: set ts=2 et sw=2 tw=80: */
 /* Any copyright is dedicated to the Public Domain.
  http://creativecommons.org/publicdomain/zero/1.0/ */
 
 "use strict";
 
 // Test that the layout-view continues to work after the page is reloaded
 
-add_task(function*() {
+add_task(function* () {
   yield addTab(URL_ROOT + "doc_layout_iframe1.html");
   let {inspector, view, testActor} = yield openLayoutView();
 
   info("Test that the layout-view works on the first page");
   yield assertLayoutView(inspector, view, testActor);
 
   info("Reload the page");
   yield testActor.reload();

--- a/devtools/client/inspector/layout/test/browser_layout_update-in-iframes.js
+++ b/devtools/client/inspector/layout/test/browser_layout_update-in-iframes.js
@@ -2,17 +2,17 @@
 /* Any copyright is dedicated to the Public Domain.
  http://creativecommons.org/publicdomain/zero/1.0/ */
 
 "use strict";
 
 // Test that the layout-view for elements within iframes also updates when they
 // change
 
-add_task(function*() {
+add_task(function* () {
   yield addTab(URL_ROOT + "doc_layout_iframe1.html");
   let {inspector, view, testActor} = yield openLayoutView();
 
   yield testResizingInIframe(inspector, view, testActor);
   yield testReflowsAfterIframeDeletion(inspector, view, testActor);
 });
 
 function* testResizingInIframe(inspector, view, testActor) {

--- a/devtools/client/inspector/markup/markup.js
+++ b/devtools/client/inspector/markup/markup.js
@@ -463,16 +463,18 @@ MarkupView.prototype = {
       parent = parent.parentNode;
     }
 
     if (container instanceof MarkupElementContainer) {
       // With the newly found container, delegate the tooltip content creation
       // and decision to show or not the tooltip
       return container.isImagePreviewTarget(target, this.tooltip);
     }
+
+    return undefined;
   },
 
   /**
    * Given the known reason, should the current selection be briefly highlighted
    * In a few cases, we don't want to highlight the node:
    * - If the reason is null (used to reset the selection),
    * - if it's "inspector-open" (when the inspector opens up, let's not
    * highlight the default node)
@@ -529,16 +531,17 @@ MarkupView.prototype = {
         return promise.reject("markupview destroyed");
       }
 
       // Mark the node as selected.
       this.markNodeAsSelected(selection.nodeFront);
 
       // Make sure the new selection receives focus so the keyboard can be used.
       this.maybeFocusNewSelection();
+      return undefined;
     }).catch(e => {
       if (!this._destroyer) {
         console.error(e);
       } else {
         console.warn("Could not mark node as selected, the markup-view was " +
           "destroyed while showing the node.");
       }
     });
@@ -702,16 +705,17 @@ MarkupView.prototype = {
         this._inspector.scrollNodeIntoView(selection);
         break;
       }
       case Ci.nsIDOMKeyEvent.DOM_VK_ESCAPE: {
         if (this.isDragging) {
           this.cancelDragging();
           break;
         }
+        // falls through
       }
       default:
         handled = false;
     }
     if (handled) {
       event.stopPropagation();
       event.preventDefault();
     }
@@ -2004,17 +2008,17 @@ MarkupContainer.prototype = {
       this._isPreDragging = true;
       this._dragStartY = event.pageY;
     }
   },
 
   /**
    * On mouse up, stop dragging.
    */
-  _onMouseUp: Task.async(function*() {
+  _onMouseUp: Task.async(function* () {
     this._isPreDragging = false;
 
     if (this.isDragging) {
       this.cancelDragging();
 
       let dropTargetNodes = this.markup.dropTargetNodes;
 
       if (!dropTargetNodes) {
@@ -2293,16 +2297,17 @@ MarkupElementContainer.prototype = Herit
         this.markup._makeTooltipPersistent(true);
         tooltip.once("hidden", () => {
           this.markup._makeTooltipPersistent(false);
         });
         tooltip.show(target);
       });
       return true;
     }
+    return undefined;
   },
 
   /**
    * Generates the an image preview for this Element. The element must be an
    * image or canvas (@see isPreviewable).
    *
    * @return {Promise} that is resolved with an object of form
    *         { data, size: { naturalWidth, naturalHeight, resizeRatio } } where
@@ -2322,17 +2327,17 @@ MarkupElementContainer.prototype = Herit
       // A preview request is already pending. Re-use that request.
       return this.tooltipDataPromise;
     }
 
     let maxDim =
       Services.prefs.getIntPref("devtools.inspector.imagePreviewTooltipSize");
 
     // Fetch the preview from the server.
-    this.tooltipDataPromise = Task.spawn(function*() {
+    this.tooltipDataPromise = Task.spawn(function* () {
       let preview = yield this.node.getImageData(maxDim);
       let data = yield preview.data.string();
 
       // Clear the pending preview request. We can't reuse the results later as
       // the preview contents might have changed.
       this.tooltipDataPromise = null;
 
       return { data, size: preview.size };

--- a/devtools/client/inspector/markup/test/browser_markup_anonymous_01.js
+++ b/devtools/client/inspector/markup/test/browser_markup_anonymous_01.js
@@ -2,17 +2,17 @@
 /* Any copyright is dedicated to the Public Domain.
  http://creativecommons.org/publicdomain/zero/1.0/ */
 
 "use strict";
 
 // Test native anonymous content in the markupview.
 const TEST_URL = URL_ROOT + "doc_markup_anonymous.html";
 
-add_task(function*() {
+add_task(function* () {
   let {inspector} = yield openInspectorForURL(TEST_URL);
 
   let pseudo = yield getNodeFront("#pseudo", inspector);
 
   // Markup looks like: <div><::before /><span /><::after /></div>
   let children = yield inspector.walker.children(pseudo);
   is(children.nodes.length, 3, "Children returned from walker");
 

--- a/devtools/client/inspector/markup/test/browser_markup_anonymous_02.js
+++ b/devtools/client/inspector/markup/test/browser_markup_anonymous_02.js
@@ -4,17 +4,17 @@
 
 "use strict";
 
 requestLongerTimeout(2);
 
 // Test XBL anonymous content in the markupview
 const TEST_URL = "chrome://devtools/content/scratchpad/scratchpad.xul";
 
-add_task(function*() {
+add_task(function* () {
   let {inspector} = yield openInspectorForURL(TEST_URL);
 
   let toolbarbutton = yield getNodeFront("toolbarbutton", inspector);
   let children = yield inspector.walker.children(toolbarbutton);
 
   is(toolbarbutton.numChildren, 3, "Correct number of children");
   is(children.nodes.length, 3, "Children returned from walker");
 

--- a/devtools/client/inspector/markup/test/browser_markup_anonymous_03.js
+++ b/devtools/client/inspector/markup/test/browser_markup_anonymous_03.js
@@ -4,17 +4,17 @@
 
 "use strict";
 
 // Test shadow DOM content in the markupview.
 // Note that many features are not yet enabled, but basic listing
 // of elements should be working.
 const TEST_URL = URL_ROOT + "doc_markup_anonymous.html";
 
-add_task(function*() {
+add_task(function* () {
   Services.prefs.setBoolPref("dom.webcomponents.enabled", true);
 
   let {inspector} = yield openInspectorForURL(TEST_URL);
 
   let shadow = yield getNodeFront("#shadow", inspector.markup);
   let children = yield inspector.walker.children(shadow);
 
   is(shadow.numChildren, 3, "Children of the shadow root are counted");

--- a/devtools/client/inspector/markup/test/browser_markup_anonymous_04.js
+++ b/devtools/client/inspector/markup/test/browser_markup_anonymous_04.js
@@ -4,17 +4,17 @@
 
 "use strict";
 
 // Test native anonymous content in the markupview with
 // devtools.inspector.showAllAnonymousContent set to true
 const TEST_URL = URL_ROOT + "doc_markup_anonymous.html";
 const PREF = "devtools.inspector.showAllAnonymousContent";
 
-add_task(function*() {
+add_task(function* () {
   Services.prefs.setBoolPref(PREF, true);
 
   let {inspector} = yield openInspectorForURL(TEST_URL);
 
   let native = yield getNodeFront("#native", inspector);
 
   // Markup looks like: <div><video controls /></div>
   let nativeChildren = yield inspector.walker.children(native);

--- a/devtools/client/inspector/markup/test/browser_markup_copy_image_data.js
+++ b/devtools/client/inspector/markup/test/browser_markup_copy_image_data.js
@@ -2,17 +2,17 @@
 /* Any copyright is dedicated to the Public Domain.
  http://creativecommons.org/publicdomain/zero/1.0/ */
 
 "use strict";
 
 // Test that image nodes have the "copy data-uri" contextual menu item enabled
 // and that clicking it puts the image data into the clipboard
 
-add_task(function*() {
+add_task(function* () {
   yield addTab(URL_ROOT + "doc_markup_image_and_canvas.html");
   let {inspector, testActor} = yield openInspector();
 
   yield selectNode("div", inspector);
   yield assertCopyImageDataNotAvailable(inspector);
 
   yield selectNode("img", inspector);
   yield assertCopyImageDataAvailable(inspector);

--- a/devtools/client/inspector/markup/test/browser_markup_css_completion_style_attribute_01.js
+++ b/devtools/client/inspector/markup/test/browser_markup_css_completion_style_attribute_01.js
@@ -64,14 +64,14 @@ const TEST_DATA = [
   ["!", "style=\"display:  inherit; color :chartreuse !important; ",
    45, 55, false],
   ["VK_RIGHT", "style=\"display:  inherit; color :chartreuse !important; ",
    55, 55, false],
   ["VK_RETURN", "style=\"display:  inherit; color :chartreuse !important;\"",
    -1, -1, false]
 ];
 
-add_task(function*() {
+add_task(function* () {
   info("Opening the inspector on the test URL");
   let {inspector} = yield openInspectorForURL(TEST_URL);
 
   yield runStyleAttributeAutocompleteTests(inspector, TEST_DATA);
 });

--- a/devtools/client/inspector/markup/test/browser_markup_css_completion_style_attribute_02.js
+++ b/devtools/client/inspector/markup/test/browser_markup_css_completion_style_attribute_02.js
@@ -91,16 +91,16 @@ const TEST_DATA_INNER = [
   [" ", "style=\"background:url('1'); ", 28, 28, false],
   ["c", "style=\"background:url('1'); color", 29, 33, true],
   ["VK_RIGHT", "style=\"background:url('1'); color", 33, 33, false],
   [":", "style=\"background:url('1'); color:aliceblue", 34, 43, true],
   ["b", "style=\"background:url('1'); color:beige", 35, 39, true],
   ["VK_RETURN", "style=\"background:url('1'); color:beige\"", -1, -1, false]
 ];
 
-add_task(function*() {
+add_task(function* () {
   info("Opening the inspector on the test URL");
   let {inspector} = yield openInspectorForURL(TEST_URL);
 
   yield runStyleAttributeAutocompleteTests(inspector, TEST_DATA_DOUBLE);
   yield runStyleAttributeAutocompleteTests(inspector, TEST_DATA_SINGLE);
   yield runStyleAttributeAutocompleteTests(inspector, TEST_DATA_INNER);
 });

--- a/devtools/client/inspector/markup/test/browser_markup_dragdrop_autoscroll.js
+++ b/devtools/client/inspector/markup/test/browser_markup_dragdrop_autoscroll.js
@@ -4,17 +4,17 @@
 
 "use strict";
 
 // Test that dragging a node near the top or bottom edge of the markup-view
 // auto-scrolls the view.
 
 const TEST_URL = URL_ROOT + "doc_markup_dragdrop_autoscroll.html";
 
-add_task(function*() {
+add_task(function* () {
   let {inspector} = yield openInspectorForURL(TEST_URL);
   let markup = inspector.markup;
   let viewHeight = markup.doc.documentElement.clientHeight;
 
   info("Pretend the markup-view is dragging");
   markup.isDragging = true;
 
   info("Simulate a mousemove on the view, at the bottom, and expect scrolling");

--- a/devtools/client/inspector/markup/test/browser_markup_dragdrop_distance.js
+++ b/devtools/client/inspector/markup/test/browser_markup_dragdrop_distance.js
@@ -9,17 +9,17 @@
 // DRAG_DROP_MIN_INITIAL_DISTANCE.
 
 const TEST_URL = URL_ROOT + "doc_markup_dragdrop.html";
 const TEST_NODE = "#test";
 
 // Keep this in sync with DRAG_DROP_MIN_INITIAL_DISTANCE in markup-view.js
 const MIN_DISTANCE = 10;
 
-add_task(function*() {
+add_task(function* () {
   let {inspector} = yield openInspectorForURL(TEST_URL);
 
   info("Drag the test node by half of the minimum distance");
   yield simulateNodeDrag(inspector, TEST_NODE, 0, MIN_DISTANCE / 2);
   yield checkIsDragging(inspector, TEST_NODE, false);
 
   info("Drag the test node by exactly the minimum distance");
   yield simulateNodeDrag(inspector, TEST_NODE, 0, MIN_DISTANCE);

--- a/devtools/client/inspector/markup/test/browser_markup_dragdrop_dragRootNode.js
+++ b/devtools/client/inspector/markup/test/browser_markup_dragdrop_dragRootNode.js
@@ -4,17 +4,17 @@
 
 "use strict";
 
 // Test that the root node isn't draggable (as well as head and body).
 
 const TEST_URL = URL_ROOT + "doc_markup_dragdrop.html";
 const TEST_DATA = ["html", "head", "body"];
 
-add_task(function*() {
+add_task(function* () {
   let {inspector} = yield openInspectorForURL(TEST_URL);
 
   for (let selector of TEST_DATA) {
     info("Try to drag/drop node " + selector);
     yield simulateNodeDrag(inspector, selector);
 
     let container = yield getContainerForSelector(selector, inspector);
     ok(!container.isDragging, "The container hasn't been marked as dragging");

--- a/devtools/client/inspector/markup/test/browser_markup_dragdrop_draggable.js
+++ b/devtools/client/inspector/markup/test/browser_markup_dragdrop_draggable.js
@@ -17,36 +17,36 @@ const TEST_DATA = [
   { node: "body", draggable: false },
   { node: "html", draggable: false },
   { node: "style", draggable: true },
   { node: "a", draggable: true },
   { node: "p", draggable: true },
   { node: "input", draggable: true },
   { node: "div", draggable: true },
   {
-    node: function*(inspector) {
+    node: function* (inspector) {
       let parentFront = yield getNodeFront("#before", inspector);
       let {nodes} = yield inspector.walker.children(parentFront);
       // Getting the comment node.
       return getContainerForNodeFront(nodes[1], inspector);
     },
     draggable: true
   },
   {
-    node: function*(inspector) {
+    node: function* (inspector) {
       let parentFront = yield getNodeFront("#test", inspector);
       let {nodes} = yield inspector.walker.children(parentFront);
       // Getting the ::before pseudo element.
       return getContainerForNodeFront(nodes[0], inspector);
     },
     draggable: false
   }
 ];
 
-add_task(function*() {
+add_task(function* () {
   let {inspector} = yield openInspectorForURL(TEST_URL);
   yield inspector.markup.expandAll();
 
   for (let {node, draggable} of TEST_DATA) {
     let container;
     let name;
     if (typeof node === "string") {
       container = yield getContainerForSelector(node, inspector);