Bug 1393464 - Remove `Heritage` from devtools helper view-helpers.js; r=pbro

Calling "devtools/shared/extend" instead.

MozReview-Commit-ID: HbonI7vq8Be

--HG--
extra : rebase_source : 5c9f2ccd0f5cddfcdb1949354932fd492564cc93

devtools/client/canvasdebugger/callslist.js

@@ -9,7 +9,7 @@
  * Functions handling details about a single recorded animation frame snapshot
  * (the calls list, rendering preview, thumbnails filmstrip etc.).
  */
-var CallsListView = Heritage.extend(WidgetMethods, {
+var CallsListView = extend(WidgetMethods, {
   /**
    * Initialization function, called when the tool is started.
    */

devtools/client/canvasdebugger/canvasdebugger.js

@@ -14,10 +14,11 @@ const EventEmitter = require("devtools/shared/old-event-emitter");
 const { CallWatcherFront } = require("devtools/shared/fronts/call-watcher");
 const { CanvasFront } = require("devtools/shared/fronts/canvas");
 const DevToolsUtils = require("devtools/shared/DevToolsUtils");
+const { extend } = require("devtools/shared/extend");
 const flags = require("devtools/shared/flags");
 const { LocalizationHelper } = require("devtools/shared/l10n");
 const { PluralForm } = require("devtools/shared/plural-form");
-const { Heritage, WidgetMethods, setNamedTimeout, clearNamedTimeout,
+const { WidgetMethods, setNamedTimeout, clearNamedTimeout,
         setConditionalTimeout } = require("devtools/client/shared/widgets/view-helpers");
 
 // Use privileged promise in panel documents to prevent having them to freeze

devtools/client/canvasdebugger/snapshotslist.js

@@ -8,7 +8,7 @@
 /**
  * Functions handling the recorded animation frame snapshots UI.
  */
-var SnapshotsListView = Heritage.extend(WidgetMethods, {
+var SnapshotsListView = extend(WidgetMethods, {
   /**
    * Initialization function, called when the tool is started.
    */

devtools/client/debugger/content/views/event-listeners-view.js

@@ -8,7 +8,8 @@
 
 const actions = require("../actions/event-listeners");
 const { bindActionCreators } = require("devtools/client/shared/vendor/redux");
-const { Heritage, WidgetMethods } = require("devtools/client/shared/widgets/view-helpers");
+const { extend } = require("devtools/shared/extend");
+const { WidgetMethods } = require("devtools/client/shared/widgets/view-helpers");
 const { SideMenuWidget } = require("resource://devtools/client/shared/widgets/SideMenuWidget.jsm");
 
 /**
@@ -26,7 +27,7 @@ function EventListenersView(controller) {
   controller.onChange("event-listeners", this.renderListeners.bind(this));
 }
 
-EventListenersView.prototype = Heritage.extend(WidgetMethods, {
+EventListenersView.prototype = extend(WidgetMethods, {
   /**
    * Initialization function, called when the debugger is started.
    */

devtools/client/debugger/content/views/sources-view.js

@@ -20,8 +20,8 @@ const actions = Object.assign(
   require("../actions/breakpoints")
 );
 const { bindActionCreators } = require("devtools/client/shared/vendor/redux");
+const { extend } = require("devtools/shared/extend");
 const {
-  Heritage,
   WidgetMethods,
   setNamedTimeout
 } = require("devtools/client/shared/widgets/view-helpers");
@@ -80,7 +80,7 @@ function SourcesView(controller, DebuggerView) {
   this._onConditionalPopupHidden = this._onConditionalPopupHidden.bind(this);
 }
 
-SourcesView.prototype = Heritage.extend(WidgetMethods, {
+SourcesView.prototype = extend(WidgetMethods, {
   /**
    * Initialization function, called when the debugger is started.
    */
@@ -350,13 +350,13 @@ SourcesView.prototype = Heritage.extend(WidgetMethods, {
     }
 
     // Create the element node and menu popup for the breakpoint item.
-    let breakpointArgs = Heritage.extend(breakpoint.asMutable(), options);
+    let breakpointArgs = extend(breakpoint.asMutable(), options);
     let breakpointView = this._createBreakpointView.call(this, breakpointArgs);
     let contextMenu = this._createContextMenu.call(this, breakpointArgs);
 
     // Append a breakpoint child item to the corresponding source item.
     sourceItem.append(breakpointView.container, {
-      attachment: Heritage.extend(breakpointArgs, {
+      attachment: extend(breakpointArgs, {
         actor: location.actor,
         line: location.line,
         view: breakpointView,

devtools/client/debugger/debugger-controller.js

@@ -109,8 +109,9 @@ const { SideMenuWidget } = require("resource://devtools/client/shared/widgets/Si
 const { VariablesView } = require("resource://devtools/client/shared/widgets/VariablesView.jsm");
 const { VariablesViewController, StackFrameUtils } = require("resource://devtools/client/shared/widgets/VariablesViewController.jsm");
 const EventEmitter = require("devtools/shared/old-event-emitter");
+const { extend } = require("devtools/shared/extend");
 const { gDevTools } = require("devtools/client/framework/devtools");
-const { ViewHelpers, Heritage, WidgetMethods, setNamedTimeout,
+const { ViewHelpers, WidgetMethods, setNamedTimeout,
         clearNamedTimeout } = require("devtools/client/shared/widgets/view-helpers");
 
 // Use privileged promise in panel documents to prevent having them to freeze

devtools/client/debugger/debugger-view.js

@@ -846,7 +846,7 @@ var DebuggerView = {
 function ResultsPanelContainer() {
 }
 
-ResultsPanelContainer.prototype = Heritage.extend(WidgetMethods, {
+ResultsPanelContainer.prototype = extend(WidgetMethods, {
   /**
    * Sets the anchor node for this container panel.
    * @param nsIDOMNode aNode

devtools/client/debugger/views/filter-view.js

@@ -551,7 +551,7 @@ function FilteredSourcesView(DebuggerView) {
   this._onSelect = this._onSelect.bind(this);
 }
 
-FilteredSourcesView.prototype = Heritage.extend(ResultsPanelContainer.prototype, {
+FilteredSourcesView.prototype = extend(ResultsPanelContainer.prototype, {
   /**
    * Initialization function, called when the debugger is started.
    */
@@ -714,7 +714,7 @@ function FilteredFunctionsView(SourceScripts, Parser, DebuggerView) {
   this._onSelect = this._onSelect.bind(this);
 }
 
-FilteredFunctionsView.prototype = Heritage.extend(ResultsPanelContainer.prototype, {
+FilteredFunctionsView.prototype = extend(ResultsPanelContainer.prototype, {
   /**
    * Initialization function, called when the debugger is started.
    */

devtools/client/debugger/views/global-search-view.js

@@ -23,7 +23,7 @@ function GlobalSearchView(DebuggerController, DebuggerView) {
   this._onMatchClick = this._onMatchClick.bind(this);
 }
 
-GlobalSearchView.prototype = Heritage.extend(WidgetMethods, {
+GlobalSearchView.prototype = extend(WidgetMethods, {
   /**
    * Initialization function, called when the debugger is started.
    */

devtools/client/debugger/views/stack-frames-classic-view.js

@@ -20,7 +20,7 @@ function StackFramesClassicListView(DebuggerController, DebuggerView) {
   this._onSelect = this._onSelect.bind(this);
 }
 
-StackFramesClassicListView.prototype = Heritage.extend(WidgetMethods, {
+StackFramesClassicListView.prototype = extend(WidgetMethods, {
   /**
    * Initialization function, called when the debugger is started.
    */

devtools/client/debugger/views/stack-frames-view.js

@@ -25,7 +25,7 @@ function StackFramesView(DebuggerController, DebuggerView) {
   this._getStackAsString = this._getStackAsString.bind(this);
 }
 
-StackFramesView.prototype = Heritage.extend(WidgetMethods, {
+StackFramesView.prototype = extend(WidgetMethods, {
   /**
    * Initialization function, called when the debugger is started.
    */

devtools/client/debugger/views/watch-expressions-view.js

@@ -29,7 +29,7 @@ function WatchExpressionsView(DebuggerController, DebuggerView) {
   this._onKeyPress = this._onKeyPress.bind(this);
 }
 
-WatchExpressionsView.prototype = Heritage.extend(WidgetMethods, {
+WatchExpressionsView.prototype = extend(WidgetMethods, {
   /**
    * Initialization function, called when the debugger is started.
    */

devtools/client/debugger/views/workers-view.js

@@ -13,7 +13,7 @@ function WorkersView() {
   this._onWorkerSelect = this._onWorkerSelect.bind(this);
 }
 
-WorkersView.prototype = Heritage.extend(WidgetMethods, {
+WorkersView.prototype = extend(WidgetMethods, {
   initialize: function () {
     if (!Prefs.workersEnabled) {
       return;

devtools/client/performance/modules/widgets/graphs.js

@@ -8,7 +8,7 @@
  */
 
 const { Task } = require("devtools/shared/task");
-const { Heritage } = require("devtools/client/shared/widgets/view-helpers");
+const { extend } = require("devtools/shared/extend");
 const LineGraphWidget = require("devtools/client/shared/widgets/LineGraphWidget");
 const MountainGraphWidget = require("devtools/client/shared/widgets/MountainGraphWidget");
 const { CanvasGraphUtils } = require("devtools/client/shared/widgets/Graphs");
@@ -59,7 +59,7 @@ function PerformanceGraph(parent, metric) {
   this.setTheme();
 }
 
-PerformanceGraph.prototype = Heritage.extend(LineGraphWidget.prototype, {
+PerformanceGraph.prototype = extend(LineGraphWidget.prototype, {
   strokeWidth: STROKE_WIDTH,
   dampenValuesFactor: DAMPEN_VALUES,
   fixedHeight: HEIGHT,
@@ -108,7 +108,7 @@ function FramerateGraph(parent) {
   PerformanceGraph.call(this, parent, ProfilerGlobal.L10N.getStr("graphs.fps"));
 }
 
-FramerateGraph.prototype = Heritage.extend(PerformanceGraph.prototype, {
+FramerateGraph.prototype = extend(PerformanceGraph.prototype, {
   mainColor: FRAMERATE_GRAPH_COLOR_NAME,
   setPerformanceData: function ({ duration, ticks }, resolution) {
     this.dataDuration = duration;
@@ -126,7 +126,7 @@ function MemoryGraph(parent) {
   PerformanceGraph.call(this, parent, ProfilerGlobal.L10N.getStr("graphs.memory"));
 }
 
-MemoryGraph.prototype = Heritage.extend(PerformanceGraph.prototype, {
+MemoryGraph.prototype = extend(PerformanceGraph.prototype, {
   mainColor: MEMORY_GRAPH_COLOR_NAME,
   setPerformanceData: function ({ duration, memory }) {
     this.dataDuration = duration;
@@ -138,7 +138,7 @@ function TimelineGraph(parent, filter) {
   MarkersOverview.call(this, parent, filter);
 }
 
-TimelineGraph.prototype = Heritage.extend(MarkersOverview.prototype, {
+TimelineGraph.prototype = extend(MarkersOverview.prototype, {
   headerHeight: MARKERS_GRAPH_HEADER_HEIGHT,
   rowHeight: MARKERS_GRAPH_ROW_HEIGHT,
   groupPadding: MARKERS_GROUP_VERTICAL_PADDING,
@@ -439,7 +439,7 @@ function OptimizationsGraph(parent) {
   this.setTheme();
 }
 
-OptimizationsGraph.prototype = Heritage.extend(MountainGraphWidget.prototype, {
+OptimizationsGraph.prototype = extend(MountainGraphWidget.prototype, {
 
   render: Task.async(function* (threadNode, frameNode) {
     // Regardless if we draw or clear the graph, wait

devtools/client/performance/modules/widgets/markers-overview.js

@@ -9,7 +9,7 @@
  * markers are visible in the "waterfall".
  */
 
-const { Heritage } = require("devtools/client/shared/widgets/view-helpers");
+const { extend } = require("devtools/shared/extend");
 const { AbstractCanvasGraph } = require("devtools/client/shared/widgets/Graphs");
 
 const { colorUtils } = require("devtools/shared/css/color");
@@ -48,7 +48,7 @@ function MarkersOverview(parent, filter = [], ...args) {
   this.setFilter(filter);
 }
 
-MarkersOverview.prototype = Heritage.extend(AbstractCanvasGraph.prototype, {
+MarkersOverview.prototype = extend(AbstractCanvasGraph.prototype, {
   clipheadLineColor: OVERVIEW_CLIPHEAD_LINE_COLOR,
   selectionLineColor: OVERVIEW_SELECTION_LINE_COLOR,
   headerHeight: OVERVIEW_HEADER_HEIGHT,

devtools/client/performance/modules/widgets/tree-view.js

@@ -9,7 +9,7 @@
  */
 
 const { L10N } = require("devtools/client/performance/modules/global");
-const { Heritage } = require("devtools/client/shared/widgets/view-helpers");
+const { extend } = require("devtools/shared/extend");
 const { AbstractTreeItem } = require("resource://devtools/client/shared/widgets/AbstractTreeItem.jsm");
 
 const URL_LABEL_TOOLTIP = L10N.getStr("table.url.tooltiptext");
@@ -174,7 +174,7 @@ function CallView({
   this._onUrlClick = this._onUrlClick.bind(this);
 }
 
-CallView.prototype = Heritage.extend(AbstractTreeItem.prototype, {
+CallView.prototype = extend(AbstractTreeItem.prototype, {
   /**
    * Creates the view for this tree node.
    * @param nsIDOMNode document

devtools/client/performance/performance-controller.js

@@ -14,10 +14,11 @@ var { loader, require } = BrowserLoaderModule.BrowserLoader({
   window
 });
 var { Task } = require("devtools/shared/task");
-/* exported Heritage, ViewHelpers, WidgetMethods, setNamedTimeout, clearNamedTimeout */
-var { Heritage, ViewHelpers, WidgetMethods, setNamedTimeout, clearNamedTimeout } = require("devtools/client/shared/widgets/view-helpers");
+/* exported ViewHelpers, WidgetMethods, setNamedTimeout, clearNamedTimeout */
+var { ViewHelpers, WidgetMethods, setNamedTimeout, clearNamedTimeout } = require("devtools/client/shared/widgets/view-helpers");
 var { PrefObserver } = require("devtools/client/shared/prefs");
-
+/* exported extend */
+const { extend } = require("devtools/shared/extend");
 // Use privileged promise in panel documents to prevent having them to freeze
 // during toolbox destruction. See bug 1402779.
 var Promise = require("Promise");

devtools/client/performance/test/helpers/synth-utils.js

@@ -55,14 +55,14 @@ exports.synthesizeProfile = () => {
 exports.synthesizeCustomTreeClass = () => {
   const { Cu } = require("chrome");
   const { AbstractTreeItem } = Cu.import("resource://devtools/client/shared/widgets/AbstractTreeItem.jsm", {});
-  const { Heritage } = require("devtools/client/shared/widgets/view-helpers");
+  const { extend } = require("devtools/shared/extend");
 
   function MyCustomTreeItem(dataSrc, properties) {
     AbstractTreeItem.call(this, properties);
     this.itemDataSrc = dataSrc;
   }
 
-  MyCustomTreeItem.prototype = Heritage.extend(AbstractTreeItem.prototype, {
+  MyCustomTreeItem.prototype = extend(AbstractTreeItem.prototype, {
     _displaySelf: function (document, arrowNode) {
       let node = document.createElement("hbox");
       node.style.marginInlineStart = (this.level * 10) + "px";

devtools/client/performance/views/details-js-call-tree.js

@@ -9,7 +9,7 @@
 /**
  * CallTree view containing profiler call tree, controlled by DetailsView.
  */
-var JsCallTreeView = Heritage.extend(DetailsSubview, {
+var JsCallTreeView = extend(DetailsSubview, {
 
   rerenderPrefs: [
     "invert-call-tree",

devtools/client/performance/views/details-js-flamegraph.js

@@ -10,7 +10,7 @@
  * FlameGraph view containing a pyramid-like visualization of a profile,
  * controlled by DetailsView.
  */
-var JsFlameGraphView = Heritage.extend(DetailsSubview, {
+var JsFlameGraphView = extend(DetailsSubview, {
 
   shouldUpdateWhileMouseIsActive: true,
 

devtools/client/performance/views/details-memory-call-tree.js

@@ -9,7 +9,7 @@
 /**
  * CallTree view containing memory allocation sites, controlled by DetailsView.
  */
-var MemoryCallTreeView = Heritage.extend(DetailsSubview, {
+var MemoryCallTreeView = extend(DetailsSubview, {
 
   rerenderPrefs: [
     "invert-call-tree"

devtools/client/performance/views/details-memory-flamegraph.js

@@ -10,7 +10,7 @@
  * FlameGraph view containing a pyramid-like visualization of memory allocation
  * sites, controlled by DetailsView.
  */
-var MemoryFlameGraphView = Heritage.extend(DetailsSubview, {
+var MemoryFlameGraphView = extend(DetailsSubview, {
 
   shouldUpdateWhileMouseIsActive: true,
 

devtools/client/performance/views/details-waterfall.js

@@ -15,7 +15,7 @@ const { TickUtils } = require("devtools/client/performance/modules/waterfall-tic
 /**
  * Waterfall view containing the timeline markers, controlled by DetailsView.
  */
-var WaterfallView = Heritage.extend(DetailsSubview, {
+var WaterfallView = extend(DetailsSubview, {
 
   // Smallest unit of time between two markers. Larger by 10x^3 than Number.EPSILON.
   MARKER_EPSILON: 0.000000000001,

devtools/client/scratchpad/scratchpad.js

@@ -55,7 +55,7 @@ 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 { extend } = require("devtools/shared/extend");
 
 const {XPCOMUtils} = require("resource://gre/modules/XPCOMUtils.jsm");
 const {NetUtil} = require("resource://gre/modules/NetUtil.jsm");
@@ -2177,7 +2177,7 @@ function ScratchpadWindow() {}
 
 ScratchpadWindow.consoleFor = ScratchpadTab.consoleFor;
 
-ScratchpadWindow.prototype = Heritage.extend(ScratchpadTab.prototype, {
+ScratchpadWindow.prototype = extend(ScratchpadTab.prototype, {
   /**
    * Attach to this window.
    *
@@ -2207,7 +2207,7 @@ function ScratchpadTarget(aTarget)
 
 ScratchpadTarget.consoleFor = ScratchpadTab.consoleFor;
 
-ScratchpadTarget.prototype = Heritage.extend(ScratchpadTab.prototype, {
+ScratchpadTarget.prototype = extend(ScratchpadTab.prototype, {
   _attach: function ST__attach()
   {
     if (this._target.isRemote) {

devtools/client/shadereditor/shadereditor.js

@@ -15,7 +15,8 @@ const EventEmitter = require("devtools/shared/old-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} =
+const {extend} = require("devtools/shared/extend");
+const {WidgetMethods, setNamedTimeout} =
   require("devtools/client/shared/widgets/view-helpers");
 const {Task} = require("devtools/shared/task");
 
@@ -198,7 +199,7 @@ var EventsHandler = {
 /**
  * Functions handling the sources UI.
  */
-var ShadersListView = Heritage.extend(WidgetMethods, {
+var ShadersListView = extend(WidgetMethods, {
   /**
    * Initialization function, called when the tool is started.
    */

devtools/client/shared/widgets/AbstractTreeItem.jsm

@@ -41,7 +41,7 @@ this.EXPORTED_SYMBOLS = ["AbstractTreeItem"];
  *   this.itemDataSrc = dataSrc;
  * }
  *
- * MyCustomTreeItem.prototype = Heritage.extend(AbstractTreeItem.prototype, {
+ * MyCustomTreeItem.prototype = extend(AbstractTreeItem.prototype, {
  *   _displaySelf: function(document, arrowNode) {
  *     let node = document.createElement("hbox");
  *     ...

devtools/client/shared/widgets/BarGraphWidget.js

@@ -1,6 +1,7 @@
 "use strict";
 
-const { Heritage, setNamedTimeout, clearNamedTimeout } = require("devtools/client/shared/widgets/view-helpers");
+const { extend } = require("devtools/shared/extend");
+const { setNamedTimeout, clearNamedTimeout } = require("devtools/client/shared/widgets/view-helpers");
 const { AbstractCanvasGraph, CanvasGraphUtils } = require("devtools/client/shared/widgets/Graphs");
 
 const HTML_NS = "http://www.w3.org/1999/xhtml";
@@ -77,7 +78,7 @@ this.BarGraphWidget = function (parent, ...args) {
   });
 };
 
-BarGraphWidget.prototype = Heritage.extend(AbstractCanvasGraph.prototype, {
+BarGraphWidget.prototype = extend(AbstractCanvasGraph.prototype, {
   clipheadLineColor: GRAPH_CLIPHEAD_LINE_COLOR,
   selectionLineColor: GRAPH_SELECTION_LINE_COLOR,
   selectionBackgroundColor: GRAPH_SELECTION_BACKGROUND_COLOR,

devtools/client/shared/widgets/LineGraphWidget.js

@@ -1,7 +1,7 @@
 "use strict";
 
 const { Task } = require("devtools/shared/task");
-const { Heritage } = require("devtools/client/shared/widgets/view-helpers");
+const { extend } = require("devtools/shared/extend");
 const { AbstractCanvasGraph, CanvasGraphUtils } = require("devtools/client/shared/widgets/Graphs");
 const { LocalizationHelper } = require("devtools/shared/l10n");
 
@@ -89,7 +89,7 @@ this.LineGraphWidget = function (parent, options = {}, ...args) {
   });
 };
 
-LineGraphWidget.prototype = Heritage.extend(AbstractCanvasGraph.prototype, {
+LineGraphWidget.prototype = extend(AbstractCanvasGraph.prototype, {
   backgroundColor: GRAPH_BACKGROUND_COLOR,
   backgroundGradientStart: GRAPH_BACKGROUND_GRADIENT_START,
   backgroundGradientEnd: GRAPH_BACKGROUND_GRADIENT_END,

devtools/client/shared/widgets/MountainGraphWidget.js

@@ -1,6 +1,6 @@
 "use strict";
 
-const { Heritage } = require("devtools/client/shared/widgets/view-helpers");
+const { extend } = require("devtools/shared/extend");
 const { AbstractCanvasGraph } = require("devtools/client/shared/widgets/Graphs");
 
 // Bar graph constants.
@@ -57,7 +57,7 @@ this.MountainGraphWidget = function (parent, ...args) {
   AbstractCanvasGraph.apply(this, [parent, "mountain-graph", ...args]);
 };
 
-MountainGraphWidget.prototype = Heritage.extend(AbstractCanvasGraph.prototype, {
+MountainGraphWidget.prototype = extend(AbstractCanvasGraph.prototype, {
   backgroundColor: GRAPH_BACKGROUND_COLOR,
   strokeColor: GRAPH_STROKE_COLOR,
   strokeWidth: GRAPH_STROKE_WIDTH,

devtools/client/shared/widgets/VariablesView.jsm

@@ -24,7 +24,8 @@ const Services = require("Services");
 const { getSourceNames } = require("devtools/client/shared/source-utils");
 const promise = require("promise");
 const defer = require("devtools/shared/defer");
-const { Heritage, ViewHelpers, setNamedTimeout } =
+const { extend } = require("devtools/shared/extend");
+const { ViewHelpers, setNamedTimeout } =
   require("devtools/client/shared/widgets/view-helpers");
 const { Task } = require("devtools/shared/task");
 const nodeConstants = require("devtools/shared/dom-node-constants");
@@ -2179,7 +2180,7 @@ function Variable(aScope, aName, aDescriptor, aOptions) {
   this.setGrip(aDescriptor.value);
 }
 
-Variable.prototype = Heritage.extend(Scope.prototype, {
+Variable.prototype = extend(Scope.prototype, {
   /**
    * Whether this Variable should be prefetched when it is remoted.
    */
@@ -3072,7 +3073,7 @@ function Property(aVar, aName, aDescriptor, aOptions) {
   Variable.call(this, aVar, aName, aDescriptor, aOptions);
 }
 
-Property.prototype = Heritage.extend(Variable.prototype, {
+Property.prototype = extend(Variable.prototype, {
   /**
    * The class name applied to this property's target element.
    */
@@ -3160,7 +3161,7 @@ VariablesView.prototype.commitHierarchy = function () {
 
 // Some variables are likely to contain a very large number of properties.
 // It would be a bad idea to re-expand them or perform expensive operations.
-VariablesView.prototype.commitHierarchyIgnoredItems = Heritage.extend(null, {
+VariablesView.prototype.commitHierarchyIgnoredItems = extend(null, {
   "window": true,
   "this": true
 });
@@ -4116,7 +4117,7 @@ function EditableName(aVariable, aOptions) {
 
 EditableName.create = Editable.create;
 
-EditableName.prototype = Heritage.extend(Editable.prototype, {
+EditableName.prototype = extend(Editable.prototype, {
   className: "element-name-input",
 
   get label() {
@@ -4138,7 +4139,7 @@ function EditableValue(aVariable, aOptions) {
 
 EditableValue.create = Editable.create;
 
-EditableValue.prototype = Heritage.extend(Editable.prototype, {
+EditableValue.prototype = extend(Editable.prototype, {
   className: "element-value-input",
 
   get label() {
@@ -4160,7 +4161,7 @@ function EditableNameAndValue(aVariable, aOptions) {
 
 EditableNameAndValue.create = Editable.create;
 
-EditableNameAndValue.prototype = Heritage.extend(EditableName.prototype, {
+EditableNameAndValue.prototype = extend(EditableName.prototype, {
   _reset: function (e) {
     // Hide the Variable or Property if the user presses escape.
     this._variable.remove();

devtools/client/shared/widgets/view-helpers.js

@@ -13,29 +13,6 @@ const WIDGET_FOCUSABLE_NODES = new Set(["vbox", "hbox"]);
 
 var namedTimeoutsStore = new Map();
 
-/**
- * Inheritance helpers from the addon SDK's core/heritage.
- * Remove these when all devtools are loadered.
- */
-exports.Heritage = {
-  /**
-   * @see extend in sdk/core/heritage.
-   */
-  extend: function (prototype, properties = {}) {
-    return Object.create(prototype, this.getOwnPropertyDescriptors(properties));
-  },
-
-  /**
-   * @see getOwnPropertyDescriptors in sdk/core/heritage.
-   */
-  getOwnPropertyDescriptors: function (object) {
-    return Object.getOwnPropertyNames(object).reduce((descriptor, name) => {
-      descriptor[name] = Object.getOwnPropertyDescriptor(object, name);
-      return descriptor;
-    }, {});
-  }
-};
-
 /**
  * Helper for draining a rapid succession of events and invoking a callback
  * once everything settles down.
@@ -490,7 +467,7 @@ Item.prototype = {
  *     this.widget = new MyWidget(document.querySelector(".my-node"));
  *   }
  *
- *   MyView.prototype = Heritage.extend(WidgetMethods, {
+ *   MyView.prototype = extend(WidgetMethods, {
  *     myMethod: function() {},
  *     ...
  *   });