--- a/devtools/client/app-manager/app-projects.js
+++ b/devtools/client/app-manager/app-projects.js
@@ -203,17 +203,17 @@ const AppProjects = {
       return store.object.projects[store.object.projects.length - 1];
     });
   },
 
   update: function (project) {
     return IDB.update(project);
   },
 
-  updateLocation: function(project, newLocation) {
+  updateLocation: function(project, newLocation) {
     return IDB.remove(project.location)
               .then(() => {
                 project.location = newLocation;
                 return IDB.add(project);
               });
   },
 
   remove: function(location) {

--- a/devtools/client/responsivedesign/responsivedesign.jsm
+++ b/devtools/client/responsivedesign/responsivedesign.jsm
@@ -228,17 +228,19 @@ function ResponsiveUI(aWindow, aTab)
     window: this.mainWindow,
     type: "deveditionpromo",
     anchor: this.chromeDoc.querySelector("#content")
   });
 }
 
 ResponsiveUI.prototype = {
   _transitionsEnabled: true,
-  get transitionsEnabled() this._transitionsEnabled,
+  get transitionsEnabled() {
+    return this._transitionsEnabled;
+  },
   set transitionsEnabled(aValue) {
     this._transitionsEnabled = aValue;
     if (aValue && !this._resizing && this.stack.hasAttribute("responsivemode")) {
       this.stack.removeAttribute("notransition");
     } else if (!aValue) {
       this.stack.setAttribute("notransition", "true");
     }
   },

--- a/devtools/client/shared/AppCacheUtils.jsm
+++ b/devtools/client/shared/AppCacheUtils.jsm
@@ -611,17 +611,17 @@ ManifestParser.prototype = {
           this._addError(this.currentLine,
                          "invalidSectionName", text, this.currentLine);
           return false;
       }
     }
   },
 };
 
-XPCOMUtils.defineLazyGetter(this, "l10n", function() Services.strings
+XPCOMUtils.defineLazyGetter(this, "l10n", () => Services.strings
   .createBundle("chrome://browser/locale/devtools/appcacheutils.properties"));
 
 XPCOMUtils.defineLazyGetter(this, "appcacheservice", function() {
   return Cc["@mozilla.org/network/application-cache-service;1"]
            .getService(Ci.nsIApplicationCacheService);
 
 });
 

--- a/devtools/client/shared/SplitView.jsm
+++ b/devtools/client/shared/SplitView.jsm
@@ -81,31 +81,40 @@ this.SplitView = function SplitView(aRoo
 }
 
 SplitView.prototype = {
   /**
     * Retrieve whether the UI currently has a landscape orientation.
     *
     * @return boolean
     */
-  get isLandscape() this._mql.matches,
+  get isLandscape()
+  {
+    return this._mql.matches;
+  },
 
   /**
     * Retrieve the root element.
     *
     * @return DOMElement
     */
-  get rootElement() this._root,
+  get rootElement()
+  {
+    return this._root;
+  },
 
   /**
     * Retrieve the active item's summary element or null if there is none.
     *
     * @return DOMElement
     */
-  get activeSummary() this._activeSummary,
+  get activeSummary()
+  {
+    return this._activeSummary;
+  },
 
   /**
     * Set the active item's summary element.
     *
     * @param DOMElement aSummary
     */
   set activeSummary(aSummary)
   {

--- a/devtools/client/shared/widgets/SideMenuWidget.jsm
+++ b/devtools/client/shared/widgets/SideMenuWidget.jsm
@@ -71,17 +71,17 @@ SideMenuWidget.prototype = {
   /**
    * Specifies if groups in this container should be sorted.
    */
   sortedGroups: true,
 
   /**
    * The comparator used to sort groups.
    */
-  groupSortPredicate: function(a, b) a.localeCompare(b),
+  groupSortPredicate: (a, b) => a.localeCompare(b),
 
   /**
    * Inserts an item in this container at the specified index, optionally
    * grouping by name.
    *
    * @param number aIndex
    *        The position in the container intended for this item.
    * @param nsIDOMNode aContents
@@ -483,18 +483,22 @@ function SideMenuGroup(aWidget, aName, a
   else {
     let target = this._target = this._list = this.document.createElement("vbox");
     target.className = "side-menu-widget-group side-menu-widget-group-list";
     target.setAttribute("merged-group-contents", "");
   }
 }
 
 SideMenuGroup.prototype = {
-  get _orderedGroupElementsArray() this.ownerView._orderedGroupElementsArray,
-  get _orderedMenuElementsArray() this.ownerView._orderedMenuElementsArray,
+  get _orderedGroupElementsArray() {
+    return this.ownerView._orderedGroupElementsArray;
+  },
+  get _orderedMenuElementsArray() {
+    return this.ownerView._orderedMenuElementsArray;
+  },
   get _itemsByElement() { return this.ownerView._itemsByElement; },
 
   /**
    * Inserts this group in the parent container at the specified index.
    *
    * @param number aIndex
    *        The position in the container intended for this group.
    */
@@ -590,18 +594,22 @@ function SideMenuItem(aGroup, aContents,
     target.setAttribute("merged-item-contents", "");
   }
 
   this._target.setAttribute("flex", "1");
   this.contents = aContents;
 }
 
 SideMenuItem.prototype = {
-  get _orderedGroupElementsArray() this.ownerView._orderedGroupElementsArray,
-  get _orderedMenuElementsArray() this.ownerView._orderedMenuElementsArray,
+  get _orderedGroupElementsArray() {
+    return this.ownerView._orderedGroupElementsArray;
+  },
+  get _orderedMenuElementsArray() {
+    return this.ownerView._orderedMenuElementsArray;
+  },
   get _itemsByElement() { return this.ownerView._itemsByElement; },
 
   /**
    * Inserts this item in the parent group at the specified index.
    *
    * @param number aIndex
    *        The position in the container intended for this item.
    * @return nsIDOMNode

--- a/devtools/client/shared/widgets/VariablesView.jsm
+++ b/devtools/client/shared/widgets/VariablesView.jsm
@@ -397,40 +397,46 @@ VariablesView.prototype = {
       this.nonEnumVisible = true;
     }
   },
 
   /**
    * Sets if the variable and property searching is enabled.
    * @param boolean aFlag
    */
-  set searchEnabled(aFlag) aFlag ? this._enableSearch() : this._disableSearch(),
+  set searchEnabled(aFlag) {
+    aFlag ? this._enableSearch() : this._disableSearch();
+  },
 
   /**
    * Gets if the variable and property searching is enabled.
    * @return boolean
    */
-  get searchEnabled() !!this._searchboxContainer,
+  get searchEnabled() {
+    return !!this._searchboxContainer;
+  },
 
   /**
    * Sets the text displayed for the searchbox in this container.
    * @param string aValue
    */
   set searchPlaceholder(aValue) {
     if (this._searchboxNode) {
       this._searchboxNode.setAttribute("placeholder", aValue);
     }
     this._searchboxPlaceholder = aValue;
   },
 
   /**
    * Gets the text displayed for the searchbox in this container.
    * @return string
    */
-  get searchPlaceholder() this._searchboxPlaceholder,
+  get searchPlaceholder() {
+    return this._searchboxPlaceholder;
+  },
 
   /**
    * Enables variable and property searching in this view.
    * Use the "searchEnabled" setter to enable searching.
    */
   _enableSearch: function() {
     // If searching was already enabled, no need to re-enable it again.
     if (this._searchboxContainer) {
@@ -992,35 +998,43 @@ VariablesView.prototype = {
       this._parent.removeAttribute("actions-first");
     }
   },
 
   /**
    * Gets the parent node holding this view.
    * @return nsIDOMNode
    */
-  get boxObject() this._list.boxObject,
+  get boxObject() {
+    return this._list.boxObject;
+  },
 
   /**
    * Gets the parent node holding this view.
    * @return nsIDOMNode
    */
-  get parentNode() this._parent,
+  get parentNode() {
+    return this._parent;
+  },
 
   /**
    * Gets the owner document holding this view.
    * @return nsIHTMLDocument
    */
-  get document() this._document || (this._document = this._parent.ownerDocument),
+  get document() {
+    return this._document || (this._document = this._parent.ownerDocument);
+  },
 
   /**
    * Gets the default window holding this view.
    * @return nsIDOMWindow
    */
-  get window() this._window || (this._window = this.document.defaultView),
+  get window() {
+    return this._window || (this._window = this.document.defaultView);
+  },
 
   _document: null,
   _window: null,
 
   _store: null,
   _itemsByElement: null,
   _prevHierarchy: null,
   _currHierarchy: null,
@@ -1582,71 +1596,91 @@ Scope.prototype = {
     this._arrow.setAttribute("invisible", "");
     this._isArrowVisible = false;
   },
 
   /**
    * Gets the visibility state.
    * @return boolean
    */
-  get visible() this._isContentVisible,
+  get visible() {
+    return this._isContentVisible;
+  },
 
   /**
    * Gets the expanded state.
    * @return boolean
    */
-  get expanded() this._isExpanded,
+  get expanded() {
+    return this._isExpanded;
+  },
 
   /**
    * Gets the header visibility state.
    * @return boolean
    */
-  get header() this._isHeaderVisible,
+  get header() {
+    return this._isHeaderVisible;
+  },
 
   /**
    * Gets the twisty visibility state.
    * @return boolean
    */
-  get twisty() this._isArrowVisible,
+  get twisty() {
+    return this._isArrowVisible;
+  },
 
   /**
    * Gets the expand lock state.
    * @return boolean
    */
-  get locked() this._isLocked,
+  get locked() {
+    return this._isLocked;
+  },
 
   /**
    * Sets the visibility state.
    * @param boolean aFlag
    */
-  set visible(aFlag) aFlag ? this.show() : this.hide(),
+  set visible(aFlag) {
+    aFlag ? this.show() : this.hide();
+  },
 
   /**
    * Sets the expanded state.
    * @param boolean aFlag
    */
-  set expanded(aFlag) aFlag ? this.expand() : this.collapse(),
+  set expanded(aFlag) {
+    aFlag ? this.expand() : this.collapse();
+  },
 
   /**
    * Sets the header visibility state.
    * @param boolean aFlag
    */
-  set header(aFlag) aFlag ? this.showHeader() : this.hideHeader(),
+  set header(aFlag) {
+    aFlag ? this.showHeader() : this.hideHeader();
+  },
 
   /**
    * Sets the twisty visibility state.
    * @param boolean aFlag
    */
-  set twisty(aFlag) aFlag ? this.showArrow() : this.hideArrow(),
+  set twisty(aFlag) {
+    aFlag ? this.showArrow() : this.hideArrow();
+  },
 
   /**
    * Sets the expand lock state.
    * @param boolean aFlag
    */
-  set locked(aFlag) this._isLocked = aFlag,
+  set locked(aFlag) {
+    this._isLocked = aFlag;
+  },
 
   /**
    * Specifies if this target node may be focused.
    * @return boolean
    */
   get focusable() {
     // Check if this target node is actually visibile.
     if (!this._nameString ||
@@ -1693,41 +1727,51 @@ Scope.prototype = {
   removeEventListener: function(aName, aCallback, aCapture) {
     this._title.removeEventListener(aName, aCallback, aCapture);
   },
 
   /**
    * Gets the id associated with this item.
    * @return string
    */
-  get id() this._idString,
+  get id() {
+    return this._idString;
+  },
 
   /**
    * Gets the name associated with this item.
    * @return string
    */
-  get name() this._nameString,
+  get name() {
+    return this._nameString;
+  },
 
   /**
    * Gets the displayed value for this item.
    * @return string
    */
-  get displayValue() this._valueString,
+  get displayValue() {
+    return this._valueString;
+  },
 
   /**
    * Gets the class names used for the displayed value.
    * @return string
    */
-  get displayValueClassName() this._valueClassName,
+  get displayValueClassName() {
+    return this._valueClassName;
+  },
 
   /**
    * Gets the element associated with this item.
    * @return nsIDOMNode
    */
-  get target() this._target,
+  get target() {
+    return this._target;
+  },
 
   /**
    * Initializes this scope's id, view and binds event listeners.
    *
    * @param string aName
    *        The scope's name.
    * @param object aFlags [optional]
    *        Additional options or flags for this scope.
@@ -1999,43 +2043,51 @@ Scope.prototype = {
 
     return null;
   },
 
   /**
    * Gets top level variables view instance.
    * @return VariablesView
    */
-  get _variablesView() this._topView || (this._topView = (function(self) {
-    let parentView = self.ownerView;
-    let topView;
-
-    while ((topView = parentView.ownerView)) {
-      parentView = topView;
-    }
-    return parentView;
-  })(this)),
+  get _variablesView() {
+    return this._topView || (this._topView = (() => {
+      let parentView = this.ownerView;
+      let topView;
+
+      while ((topView = parentView.ownerView)) {
+        parentView = topView;
+      }
+      return parentView;
+    })());
+  },
 
   /**
    * Gets the parent node holding this scope.
    * @return nsIDOMNode
    */
-  get parentNode() this.ownerView._list,
+  get parentNode() {
+    return this.ownerView._list;
+  },
 
   /**
    * Gets the owner document holding this scope.
    * @return nsIHTMLDocument
    */
-  get document() this._document || (this._document = this.ownerView.document),
+  get document() {
+    return this._document || (this._document = this.ownerView.document);
+  },
 
   /**
    * Gets the default window holding this scope.
    * @return nsIDOMWindow
    */
-  get window() this._window || (this._window = this.ownerView.window),
+  get window() {
+    return this._window || (this._window = this.ownerView.window);
+  },
 
   _topView: null,
   _document: null,
   _window: null,
 
   ownerView: null,
   eval: null,
   switch: null,
@@ -2328,29 +2380,35 @@ Variable.prototype = Heritage.extend(Sco
     }
     return path;
   },
 
   /**
    * Returns this variable's value from the descriptor if available.
    * @return any
    */
-  get value() this._initialDescriptor.value,
+  get value() {
+    return this._initialDescriptor.value;
+  },
 
   /**
    * Returns this variable's getter from the descriptor if available.
    * @return object
    */
-  get getter() this._initialDescriptor.get,
+  get getter() {
+    return this._initialDescriptor.get;
+  },
 
   /**
    * Returns this variable's getter from the descriptor if available.
    * @return object
    */
-  get setter() this._initialDescriptor.set,
+  get setter() {
+    return this._initialDescriptor.set;
+  },
 
   /**
    * Sets the specific grip for this variable (applies the text content and
    * class name to the value label).
    *
    * The grip should contain the value or the type & class, as defined in the
    * remote debugger protocol. For convenience, undefined and null are
    * both considered types.

--- a/devtools/client/shared/widgets/ViewHelpers.jsm
+++ b/devtools/client/shared/widgets/ViewHelpers.jsm
@@ -766,17 +766,19 @@ this.WidgetMethods = {
       aWidget.on("mousePress", this._onWidgetMousePress.bind(this));
     }
   },
 
   /**
    * Gets the element node or widget associated with this container.
    * @return nsIDOMNode | object
    */
-  get widget() this._widget,
+  get widget() {
+    return this._widget;
+  },
 
   /**
    * Prepares an item to be added to this container. This allows, for example,
    * for a large number of items to be batched up before being sorted & added.
    *
    * If the "staged" flag is *not* set to true, the item will be immediately
    * inserted at the correct position in this container, so that all the items
    * still remain sorted. This can (possibly) be much slower than batching up