--- a/devtools/client/canvasdebugger/test/head.js
+++ b/devtools/client/canvasdebugger/test/head.js
@@ -4,16 +4,17 @@
 
 var { classes: Cc, interfaces: Ci, utils: Cu, results: Cr } = Components;
 
 var { generateUUID } = Cc["@mozilla.org/uuid-generator;1"].getService(Ci.nsIUUIDGenerator);
 var { require } = Cu.import("resource://devtools/shared/Loader.jsm", {});
 
 var Services = require("Services");
 var promise = require("promise");
+const defer = require("devtools/shared/defer");
 var { gDevTools } = require("devtools/client/framework/devtools");
 var { DebuggerClient } = require("devtools/shared/client/main");
 var { DebuggerServer } = require("devtools/server/main");
 var { CallWatcherFront } = require("devtools/shared/fronts/call-watcher");
 var { CanvasFront } = require("devtools/shared/fronts/canvas");
 var DevToolsUtils = require("devtools/shared/DevToolsUtils");
 var flags = require("devtools/shared/flags");
 var { TargetFactory } = require("devtools/client/framework/target");

--- a/devtools/client/dom/dom-panel.js
+++ b/devtools/client/dom/dom-panel.js
@@ -5,16 +5,17 @@
  * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
 "use strict";
 
 const { Cu } = require("chrome");
 const defer = require("devtools/shared/defer");
 const { ObjectClient } = require("devtools/shared/client/main");
 
 const promise = require("promise");
+const defer = require("devtools/shared/defer");
 const EventEmitter = require("devtools/shared/event-emitter");
 const { Task } = require("devtools/shared/task");
 
 /**
  * This object represents DOM panel. It's responsibility is to
  * render Document Object Model of the current debugger target.
  */
 function DomPanel(iframeWindow, toolbox) {

--- a/devtools/client/performance/modules/widgets/graphs.js
+++ b/devtools/client/performance/modules/widgets/graphs.js
@@ -9,16 +9,17 @@
 
 const { Task } = require("devtools/shared/task");
 const { Heritage } = require("devtools/client/shared/widgets/view-helpers");
 const LineGraphWidget = require("devtools/client/shared/widgets/LineGraphWidget");
 const MountainGraphWidget = require("devtools/client/shared/widgets/MountainGraphWidget");
 const { CanvasGraphUtils } = require("devtools/client/shared/widgets/Graphs");
 
 const promise = require("promise");
+const defer = require("devtools/shared/defer");
 const EventEmitter = require("devtools/shared/event-emitter");
 
 const { colorUtils } = require("devtools/shared/css/color");
 const { getColor } = require("devtools/client/shared/theme");
 const ProfilerGlobal = require("devtools/client/performance/modules/global");
 const { MarkersOverview } = require("devtools/client/performance/modules/widgets/markers-overview");
 const { createTierGraphDataFromFrameNode } = require("devtools/client/performance/modules/logic/jit");
 

--- a/devtools/client/performance/performance-controller.js
+++ b/devtools/client/performance/performance-controller.js
@@ -35,16 +35,17 @@ var Waterfall = React.createFactory(requ
 var JITOptimizationsView = React.createFactory(require("devtools/client/performance/components/jit-optimizations"));
 var RecordingControls = React.createFactory(require("devtools/client/performance/components/recording-controls"));
 var RecordingButton = React.createFactory(require("devtools/client/performance/components/recording-button"));
 var RecordingList = React.createFactory(require("devtools/client/performance/components/recording-list"));
 var RecordingListItem = React.createFactory(require("devtools/client/performance/components/recording-list-item"));
 
 var Services = require("Services");
 var promise = require("promise");
+const defer = require("devtools/shared/defer");
 var EventEmitter = require("devtools/shared/event-emitter");
 var DevToolsUtils = require("devtools/shared/DevToolsUtils");
 var flags = require("devtools/shared/flags");
 var system = require("devtools/shared/system");
 
 // Logic modules
 /* exported L10N, PerformanceTelemetry, TIMELINE_BLUEPRINT, RecordingUtils,
    PerformanceUtils, OptimizationsGraph, GraphsController,

--- a/devtools/client/scratchpad/scratchpad-panel.js
+++ b/devtools/client/scratchpad/scratchpad-panel.js
@@ -3,16 +3,17 @@
 /* This Source Code Form is subject to the terms of the Mozilla Public
  * License, v. 2.0. If a copy of the MPL was not distributed with this
  * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
 "use strict";
 
 const {Cu} = require("chrome");
 const EventEmitter = require("devtools/shared/event-emitter");
 const promise = require("promise");
+const defer = require("devtools/shared/defer");
 
 
 function ScratchpadPanel(iframeWindow, toolbox) {
   let { Scratchpad } = iframeWindow;
   this._toolbox = toolbox;
   this.panelWin = iframeWindow;
   this.scratchpad = Scratchpad;
 

--- a/devtools/client/scratchpad/scratchpad.js
+++ b/devtools/client/scratchpad/scratchpad.js
@@ -47,16 +47,17 @@ const {require, loader} = Cu.import("res
 
 const Editor = require("devtools/client/sourceeditor/editor");
 const TargetFactory = require("devtools/client/framework/target").TargetFactory;
 const EventEmitter = require("devtools/shared/event-emitter");
 const {DevToolsWorker} = require("devtools/shared/worker/worker");
 const DevToolsUtils = require("devtools/shared/DevToolsUtils");
 const flags = require("devtools/shared/flags");
 const promise = require("promise");
+const defer = require("devtools/shared/defer");
 const Services = require("Services");
 const {gDevTools} = require("devtools/client/framework/devtools");
 const {Heritage} = require("devtools/client/shared/widgets/view-helpers");
 
 const {XPCOMUtils} = require("resource://gre/modules/XPCOMUtils.jsm");
 const {NetUtil} = require("resource://gre/modules/NetUtil.jsm");
 const {ScratchpadManager} = require("resource://devtools/client/scratchpad/scratchpad-manager.jsm");
 const {addDebuggerToGlobal} = require("resource://gre/modules/jsdebugger.jsm");

--- a/devtools/client/scratchpad/test/head.js
+++ b/devtools/client/scratchpad/test/head.js
@@ -8,16 +8,17 @@ const {NetUtil} = Cu.import("resource://
 const {FileUtils} = Cu.import("resource://gre/modules/FileUtils.jsm", {});
 const {console} = Cu.import("resource://gre/modules/Console.jsm", {});
 const {ScratchpadManager} = Cu.import("resource://devtools/client/scratchpad/scratchpad-manager.jsm", {});
 const {require} = Cu.import("resource://devtools/shared/Loader.jsm", {});
 const Services = require("Services");
 const DevToolsUtils = require("devtools/shared/DevToolsUtils");
 const flags = require("devtools/shared/flags");
 const promise = require("promise");
+const defer = require("devtools/shared/defer");
 
 
 var gScratchpadWindow; // Reference to the Scratchpad chrome window object
 
 flags.testing = true;
 registerCleanupFunction(() => {
   flags.testing = false;
 });

--- a/devtools/client/shadereditor/shadereditor.js
+++ b/devtools/client/shadereditor/shadereditor.js
@@ -4,16 +4,17 @@
 "use strict";
 
 var { classes: Cc, interfaces: Ci, utils: Cu, results: Cr } = Components;
 
 const {require} = Cu.import("resource://devtools/shared/Loader.jsm", {});
 const {XPCOMUtils} = require("resource://gre/modules/XPCOMUtils.jsm");
 const {SideMenuWidget} = require("resource://devtools/client/shared/widgets/SideMenuWidget.jsm");
 const promise = require("promise");
+const defer = require("devtools/shared/defer");
 const Services = require("Services");
 const EventEmitter = require("devtools/shared/event-emitter");
 const Tooltip = require("devtools/client/shared/widgets/tooltip/Tooltip");
 const Editor = require("devtools/client/sourceeditor/editor");
 const {LocalizationHelper} = require("devtools/shared/l10n");
 const {Heritage, WidgetMethods, setNamedTimeout} =
   require("devtools/client/shared/widgets/view-helpers");
 const {Task} = require("devtools/shared/task");

--- a/devtools/client/shadereditor/test/head.js
+++ b/devtools/client/shadereditor/test/head.js
@@ -4,16 +4,17 @@
 
 var { classes: Cc, interfaces: Ci, utils: Cu, results: Cr } = Components;
 
 var { require } = Cu.import("resource://devtools/shared/Loader.jsm", {});
 var { Task } = require("devtools/shared/task");
 
 var Services = require("Services");
 var promise = require("promise");
+const defer = require("devtools/shared/defer");
 var { gDevTools } = require("devtools/client/framework/devtools");
 var { DebuggerClient } = require("devtools/shared/client/main");
 var { DebuggerServer } = require("devtools/server/main");
 var { WebGLFront } = require("devtools/shared/fronts/webgl");
 var DevToolsUtils = require("devtools/shared/DevToolsUtils");
 var flags = require("devtools/shared/flags");
 var { TargetFactory } = require("devtools/client/framework/target");
 var { Toolbox } = require("devtools/client/framework/toolbox");

--- a/devtools/client/webconsole/hudservice.js
+++ b/devtools/client/webconsole/hudservice.js
@@ -6,16 +6,17 @@
 
 var WebConsoleUtils = require("devtools/client/webconsole/utils").Utils;
 const {extend} = require("devtools/shared/extend");
 var {TargetFactory} = require("devtools/client/framework/target");
 var {gDevToolsBrowser} = require("devtools/client/framework/devtools-browser");
 var {Tools} = require("devtools/client/definitions");
 const { Task } = require("devtools/shared/task");
 var promise = require("promise");
+const defer = require("devtools/shared/defer");
 var Services = require("Services");
 loader.lazyRequireGetter(this, "Telemetry", "devtools/client/shared/telemetry");
 loader.lazyRequireGetter(this, "WebConsoleFrame", "devtools/client/webconsole/webconsole", true);
 loader.lazyRequireGetter(this, "NewWebConsoleFrame", "devtools/client/webconsole/new-webconsole", true);
 loader.lazyRequireGetter(this, "gDevTools", "devtools/client/framework/devtools", true);
 loader.lazyRequireGetter(this, "DebuggerServer", "devtools/server/main", true);
 loader.lazyRequireGetter(this, "DebuggerClient", "devtools/shared/client/main", true);
 loader.lazyRequireGetter(this, "showDoorhanger", "devtools/client/shared/doorhanger", true);

--- a/devtools/client/webconsole/jsterm.js
+++ b/devtools/client/webconsole/jsterm.js
@@ -4,16 +4,17 @@
  * License, v. 2.0. If a copy of the MPL was not distributed with this
  * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
 
 "use strict";
 
 const {Utils: WebConsoleUtils} =
   require("devtools/client/webconsole/utils");
 const promise = require("promise");
+const defer = require("devtools/shared/defer");
 const Debugger = require("Debugger");
 const Services = require("Services");
 const {KeyCodes} = require("devtools/client/shared/keycodes");
 
 loader.lazyServiceGetter(this, "clipboardHelper",
                          "@mozilla.org/widget/clipboardhelper;1",
                          "nsIClipboardHelper");
 loader.lazyRequireGetter(this, "EventEmitter", "devtools/shared/event-emitter");

--- a/devtools/client/webconsole/net/data-provider.js
+++ b/devtools/client/webconsole/net/data-provider.js
@@ -1,14 +1,15 @@
 /* This Source Code Form is subject to the terms of the Mozilla Public
  * License, v. 2.0. If a copy of the MPL was not distributed with this
  * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
 "use strict";
 
 const promise = require("promise");
+const defer = require("devtools/shared/defer");
 
 /**
  * Map of pending requests. Used mainly by tests to wait
  * till things are ready.
  */
 var promises = new Map();
 
 /**

--- a/devtools/client/webconsole/panel.js
+++ b/devtools/client/webconsole/panel.js
@@ -2,16 +2,17 @@
 /* vim: set ft= javascript ts=2 et sw=2 tw=80: */
 /* This Source Code Form is subject to the terms of the Mozilla Public
  * License, v. 2.0. If a copy of the MPL was not distributed with this
  * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
 
 "use strict";
 
 const promise = require("promise");
+const defer = require("devtools/shared/defer");
 
 loader.lazyGetter(this, "HUDService", () => require("devtools/client/webconsole/hudservice"));
 loader.lazyGetter(this, "EventEmitter", () => require("devtools/shared/event-emitter"));
 
 /**
  * A DevToolPanel that controls the Web Console.
  */
 function WebConsolePanel(iframeWindow, toolbox) {

--- a/devtools/client/webconsole/webconsole.js
+++ b/devtools/client/webconsole/webconsole.js
@@ -10,16 +10,17 @@ const {Cc, Ci, Cu} = require("chrome");
 
 const {Utils: WebConsoleUtils, CONSOLE_WORKER_IDS} =
   require("devtools/client/webconsole/utils");
 const { getSourceNames } = require("devtools/client/shared/source-utils");
 const BrowserLoaderModule = {};
 Cu.import("resource://devtools/client/shared/browser-loader.js", BrowserLoaderModule);
 
 const promise = require("promise");
+const defer = require("devtools/shared/defer");
 const Services = require("Services");
 const Telemetry = require("devtools/client/shared/telemetry");
 const {PrefObserver} = require("devtools/client/shared/prefs");
 
 loader.lazyServiceGetter(this, "clipboardHelper",
                          "@mozilla.org/widget/clipboardhelper;1",
                          "nsIClipboardHelper");
 loader.lazyRequireGetter(this, "EventEmitter", "devtools/shared/event-emitter");

--- a/devtools/server/actors/canvas.js
+++ b/devtools/server/actors/canvas.js
@@ -1,16 +1,17 @@
 /* This Source Code Form is subject to the terms of the Mozilla Public
  * License, v. 2.0. If a copy of the MPL was not distributed with this
  * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
 "use strict";
 
 /* global XPCNativeWrapper */
 
 const promise = require("promise");
+const defer = require("devtools/shared/defer");
 const protocol = require("devtools/shared/protocol");
 const {CallWatcherActor} = require("devtools/server/actors/call-watcher");
 const {CallWatcherFront} = require("devtools/shared/fronts/call-watcher");
 const {WebGLPrimitiveCounter} = require("devtools/server/primitive");
 const {
   frameSnapshotSpec,
   canvasSpec,
   CANVAS_CONTEXTS,

--- a/devtools/server/actors/device.js
+++ b/devtools/server/actors/device.js
@@ -2,16 +2,17 @@
  * License, v. 2.0. If a copy of the MPL was not distributed with this
  * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
 
 "use strict";
 
 const Services = require("Services");
 const protocol = require("devtools/shared/protocol");
 const promise = require("promise");
+const defer = require("devtools/shared/defer");
 const {LongStringActor} = require("devtools/server/actors/string");
 const {DebuggerServer} = require("devtools/server/main");
 const {getSystemInfo, getSetting} = require("devtools/shared/system");
 const {deviceSpec} = require("devtools/shared/specs/device");
 const FileReader = require("FileReader");
 
 exports.DeviceActor = protocol.ActorClassWithSpec(deviceSpec, {
   _desc: null,

--- a/devtools/server/actors/inspector.js
+++ b/devtools/server/actors/inspector.js
@@ -51,16 +51,17 @@
  */
 
 const {Cc, Ci, Cu} = require("chrome");
 const Services = require("Services");
 const protocol = require("devtools/shared/protocol");
 const {LayoutActor} = require("devtools/server/actors/layout");
 const {LongStringActor} = require("devtools/server/actors/string");
 const promise = require("promise");
+const defer = require("devtools/shared/defer");
 const {Task} = require("devtools/shared/task");
 const events = require("sdk/event/core");
 const {WalkerSearch} = require("devtools/server/actors/utils/walker-search");
 const {PageStyleActor, getFontPreviewData} = require("devtools/server/actors/styles");
 const {
   HighlighterActor,
   CustomHighlighterActor,
   isTypeRegistered,

--- a/devtools/server/actors/storage.js
+++ b/devtools/server/actors/storage.js
@@ -6,16 +6,17 @@
 
 const {Cc, Ci, Cu, CC} = require("chrome");
 const events = require("sdk/event/core");
 const protocol = require("devtools/shared/protocol");
 const {LongStringActor} = require("devtools/server/actors/string");
 const {DebuggerServer} = require("devtools/server/main");
 const Services = require("Services");
 const promise = require("promise");
+const defer = require("devtools/shared/defer");
 const {isWindowIncluded} = require("devtools/shared/layout/utils");
 const specs = require("devtools/shared/specs/storage");
 const { Task } = require("devtools/shared/task");
 
 const DEFAULT_VALUE = "value";
 
 loader.lazyRequireGetter(this, "naturalSortCaseInsensitive",
   "devtools/client/shared/natural-sort", true);

--- a/devtools/server/actors/stylesheets.js
+++ b/devtools/server/actors/stylesheets.js
@@ -3,16 +3,17 @@
  * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
 
 "use strict";
 
 const {Cc, Ci} = require("chrome");
 const Services = require("Services");
 const {XPCOMUtils} = require("resource://gre/modules/XPCOMUtils.jsm");
 const promise = require("promise");
+const defer = require("devtools/shared/defer");
 const {Task} = require("devtools/shared/task");
 const events = require("sdk/event/core");
 const protocol = require("devtools/shared/protocol");
 const {LongStringActor} = require("devtools/server/actors/string");
 const {fetch} = require("devtools/shared/DevToolsUtils");
 const {listenOnce} = require("devtools/shared/async-utils");
 const {originalSourceSpec, mediaRuleSpec, styleSheetSpec,
        styleSheetsSpec} = require("devtools/shared/specs/stylesheets");

--- a/devtools/server/actors/webbrowser.js
+++ b/devtools/server/actors/webbrowser.js
@@ -4,16 +4,17 @@
  * License, v. 2.0. If a copy of the MPL was not distributed with this
  * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
 
 "use strict";
 
 var { Ci } = require("chrome");
 var Services = require("Services");
 var promise = require("promise");
+const defer = require("devtools/shared/defer");
 var { DebuggerServer } = require("devtools/server/main");
 var DevToolsUtils = require("devtools/shared/DevToolsUtils");
 
 loader.lazyRequireGetter(this, "RootActor", "devtools/server/actors/root", true);
 loader.lazyRequireGetter(this, "BrowserAddonActor", "devtools/server/actors/addon", true);
 loader.lazyRequireGetter(this, "WebExtensionParentActor", "devtools/server/actors/webextension-parent", true);
 loader.lazyRequireGetter(this, "WorkerActorList", "devtools/server/actors/worker-list", true);
 loader.lazyRequireGetter(this, "ServiceWorkerRegistrationActorList", "devtools/server/actors/worker-list", true);

--- a/devtools/server/actors/webgl.js
+++ b/devtools/server/actors/webgl.js
@@ -3,16 +3,17 @@
  * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
 "use strict";
 
 /* global XPCNativeWrapper */
 
 const {Cu} = require("chrome");
 const events = require("sdk/event/core");
 const promise = require("promise");
+const defer = require("devtools/shared/defer");
 const protocol = require("devtools/shared/protocol");
 const { ContentObserver } = require("devtools/shared/content-observer");
 const { on, off, emit } = events;
 const {
   shaderSpec,
   programSpec,
   webGLSpec,
 } = require("devtools/shared/specs/webgl");

--- a/devtools/server/tests/mochitest/inspector-helpers.js
+++ b/devtools/server/tests/mochitest/inspector-helpers.js
@@ -8,16 +8,17 @@ var Cu = Components.utils;
 
 const {require} = Cu.import("resource://devtools/shared/Loader.jsm", {});
 const {DebuggerClient} = require("devtools/shared/client/main");
 const {DebuggerServer} = require("devtools/server/main");
 const { Task } = require("devtools/shared/task");
 
 const Services = require("Services");
 const promise = require("promise");
+const defer = require("devtools/shared/defer");
 const {_documentWalker} = require("devtools/server/actors/inspector");
 
 // Always log packets when running tests.
 Services.prefs.setBoolPref("devtools.debugger.log", true);
 SimpleTest.registerCleanupFunction(function () {
   Services.prefs.clearUserPref("devtools.debugger.log");
 });
 

--- a/devtools/server/tests/unit/head_dbg.js
+++ b/devtools/server/tests/unit/head_dbg.js
@@ -20,16 +20,17 @@ Cu.import("resource://testing-common/App
   version: "1",
   platformVersion: "42",
   crashReporter: true,
 });
 
 const { require, loader } = Cu.import("resource://devtools/shared/Loader.jsm", {});
 const { worker } = Cu.import("resource://devtools/shared/worker/loader.js", {});
 const promise = require("promise");
+const defer = require("devtools/shared/defer");
 const { Task } = require("devtools/shared/task");
 const { console } = require("resource://gre/modules/Console.jsm");
 const { NetUtil } = require("resource://gre/modules/NetUtil.jsm");
 
 const Services = require("Services");
 // Always log packets when running tests. runxpcshelltests.py will throw
 // the output away anyway, unless you give it the --verbose flag.
 Services.prefs.setBoolPref("devtools.debugger.log", true);

--- a/devtools/server/worker.js
+++ b/devtools/server/worker.js
@@ -24,16 +24,17 @@ this.rpc = function (method, ...params) 
   let deferred = Promise.defer();
   rpcDeferreds[id] = deferred;
   return deferred.promise;
 };
 
 loadSubScript("resource://devtools/shared/worker/loader.js");
 
 var Promise = worker.require("promise");
+const defer = require("devtools/shared/defer");
 var { ActorPool } = worker.require("devtools/server/actors/common");
 var { ThreadActor } = worker.require("devtools/server/actors/script");
 var { WebConsoleActor } = worker.require("devtools/server/actors/webconsole");
 var { TabSources } = worker.require("devtools/server/actors/utils/TabSources");
 var makeDebugger = worker.require("devtools/server/actors/utils/make-debugger");
 var { DebuggerServer } = worker.require("devtools/server/main");
 
 DebuggerServer.init();

--- a/devtools/shared/webconsole/test/unit/test_throttle.js
+++ b/devtools/shared/webconsole/test/unit/test_throttle.js
@@ -3,16 +3,17 @@
 
 "use strict";
 
 const Cu = Components.utils;
 const Cc = Components.classes;
 const Ci = Components.interfaces;
 const { require } = Cu.import("resource://devtools/shared/Loader.jsm", {});
 const promise = require("promise");
+const defer = require("devtools/shared/defer");
 const { NetworkThrottleManager } =
       require("devtools/shared/webconsole/throttle");
 const nsIScriptableInputStream = Ci.nsIScriptableInputStream;
 
 function TestStreamListener() {
   this.state = "initial";
 }
 TestStreamListener.prototype = {