--- a/.eslintignore
+++ b/.eslintignore
@@ -50,17 +50,16 @@ xulrunner/**
 # b2g exclusions (pref files).
 b2g/app/b2g.js
 b2g/graphene/graphene.js
 b2g/locales/en-US/b2g-l10n.js
 
 # browser/ exclusions
 browser/app/**
 browser/branding/**/firefox-branding.js
-browser/base/content/sanitizeDialog.js
 browser/base/content/test/general/file_csp_block_all_mixedcontent.html
 browser/base/content/test/urlbar/file_blank_but_not_blank.html
 browser/base/content/newtab/**
 browser/components/downloads/**
 # Test files that are really json not js, and don't need to be linted.
 browser/components/sessionstore/test/unit/data/sessionstore_valid.js
 browser/components/sessionstore/test/unit/data/sessionstore_invalid.js
 browser/components/tabview/**

--- a/browser/base/content/sanitizeDialog.js
+++ b/browser/base/content/sanitizeDialog.js
@@ -6,66 +6,59 @@
 var Cc = Components.classes;
 var Ci = Components.interfaces;
 var Cu = Components.utils;
 
 var {Sanitizer} = Cu.import("resource:///modules/Sanitizer.jsm", {});
 
 var gSanitizePromptDialog = {
 
-  get bundleBrowser()
-  {
+  get bundleBrowser() {
     if (!this._bundleBrowser)
       this._bundleBrowser = document.getElementById("bundleBrowser");
     return this._bundleBrowser;
   },
 
-  get selectedTimespan()
-  {
+  get selectedTimespan() {
     var durList = document.getElementById("sanitizeDurationChoice");
     return parseInt(durList.value);
   },
 
-  get sanitizePreferences()
-  {
+  get sanitizePreferences() {
     if (!this._sanitizePreferences) {
       this._sanitizePreferences =
         document.getElementById("sanitizePreferences");
     }
     return this._sanitizePreferences;
   },
 
-  get warningBox()
-  {
+  get warningBox() {
     return document.getElementById("sanitizeEverythingWarningBox");
   },
 
-  init: function ()
-  {
+  init() {
     // This is used by selectByTimespan() to determine if the window has loaded.
     this._inited = true;
 
     var s = new Sanitizer();
     s.prefDomain = "privacy.cpd.";
 
     document.documentElement.getButton("accept").label =
       this.bundleBrowser.getString("sanitizeButtonOK");
 
     if (this.selectedTimespan === Sanitizer.TIMESPAN_EVERYTHING) {
       this.prepareWarning();
       this.warningBox.hidden = false;
       document.title =
         this.bundleBrowser.getString("sanitizeDialog2.everything.title");
-    }
-    else
+    } else
       this.warningBox.hidden = true;
   },
 
-  selectByTimespan: function ()
-  {
+  selectByTimespan() {
     // This method is the onselect handler for the duration dropdown.  As a
     // result it's called a couple of times before onload calls init().
     if (!this._inited)
       return;
 
     var warningBox = this.warningBox;
 
     // If clearing everything
@@ -84,18 +77,17 @@ var gSanitizePromptDialog = {
     if (!warningBox.hidden) {
       window.resizeBy(0, -warningBox.boxObject.height);
       warningBox.hidden = true;
     }
     window.document.title =
       window.document.documentElement.getAttribute("noneverythingtitle");
   },
 
-  sanitize: function ()
-  {
+  sanitize() {
     // Update pref values before handing off to the sanitizer (bug 453440)
     this.updatePrefs();
     var s = new Sanitizer();
     s.prefDomain = "privacy.cpd.";
 
     s.range = Sanitizer.getClearRange(this.selectedTimespan);
     s.ignoreTimespan = !s.range;
 
@@ -109,90 +101,86 @@ var gSanitizePromptDialog = {
     acceptButton.setAttribute("label",
                               this.bundleBrowser.getString("sanitizeButtonClearing"));
     docElt.getButton("cancel").disabled = true;
 
     try {
       s.sanitize().then(null, Components.utils.reportError)
                   .then(() => window.close())
                   .then(null, Components.utils.reportError);
+      return false;
     } catch (er) {
       Components.utils.reportError("Exception during sanitize: " + er);
       return true; // We *do* want to close immediately on error.
     }
   },
 
   /**
    * If the panel that displays a warning when the duration is "Everything" is
    * not set up, sets it up.  Otherwise does nothing.
    *
    * @param aDontShowItemList Whether only the warning message should be updated.
    *                          True means the item list visibility status should not
    *                          be changed.
    */
-  prepareWarning: function (aDontShowItemList) {
+  prepareWarning(aDontShowItemList) {
     // If the date and time-aware locale warning string is ever used again,
     // initialize it here.  Currently we use the no-visits warning string,
     // which does not include date and time.  See bug 480169 comment 48.
 
     var warningStringID;
     if (this.hasNonSelectedItems()) {
       warningStringID = "sanitizeSelectedWarning";
       if (!aDontShowItemList)
         this.showItemList();
-    }
-    else {
+    } else {
       warningStringID = "sanitizeEverythingWarning2";
     }
 
     var warningDesc = document.getElementById("sanitizeEverythingWarning");
     warningDesc.textContent =
       this.bundleBrowser.getString(warningStringID);
   },
 
   /**
    * Called when the value of a preference element is synced from the actual
    * pref.  Enables or disables the OK button appropriately.
    */
-  onReadGeneric: function ()
-  {
+  onReadGeneric() {
     var found = false;
 
     // Find any other pref that's checked and enabled.
     var i = 0;
     while (!found && i < this.sanitizePreferences.childNodes.length) {
       var preference = this.sanitizePreferences.childNodes[i];
 
       found = !!preference.value &&
               !preference.disabled;
       i++;
     }
 
     try {
       document.documentElement.getButton("accept").disabled = !found;
-    }
-    catch (e) { }
+    } catch (e) { }
 
     // Update the warning prompt if needed
     this.prepareWarning(true);
 
     return undefined;
   },
 
   /**
    * Sanitizer.prototype.sanitize() requires the prefs to be up-to-date.
    * Because the type of this prefwindow is "child" -- and that's needed because
    * without it the dialog has no OK and Cancel buttons -- the prefs are not
    * updated on dialogaccept on platforms that don't support instant-apply
    * (i.e., Windows).  We must therefore manually set the prefs from their
    * corresponding preference elements.
    */
-  updatePrefs : function ()
-  {
-    var tsPref = document.getElementById("privacy.sanitize.timeSpan");
+  updatePrefs() {
     Sanitizer.prefs.setIntPref("timeSpan", this.selectedTimespan);
 
     // Keep the pref for the download history in sync with the history pref.
     document.getElementById("privacy.cpd.downloads").value =
       document.getElementById("privacy.cpd.history").value;
 
     // Now manually set the prefs from their corresponding preference
     // elements.
@@ -201,60 +189,59 @@ var gSanitizePromptDialog = {
       var p = this.sanitizePreferences.childNodes[i];
       prefs.setBoolPref(p.name, p.value);
     }
   },
 
   /**
    * Check if all of the history items have been selected like the default status.
    */
-  hasNonSelectedItems: function () {
+  hasNonSelectedItems() {
     let checkboxes = document.querySelectorAll("#itemList > [preference]");
     for (let i = 0; i < checkboxes.length; ++i) {
       let pref = document.getElementById(checkboxes[i].getAttribute("preference"));
       if (!pref.value)
         return true;
     }
     return false;
   },
 
   /**
    * Show the history items list.
    */
-  showItemList: function () {
+  showItemList() {
     var itemList = document.getElementById("itemList");
     var expanderButton = document.getElementById("detailsExpander");
 
     if (itemList.collapsed) {
       expanderButton.className = "expander-up";
       itemList.setAttribute("collapsed", "false");
       if (document.documentElement.boxObject.height)
         window.resizeBy(0, itemList.boxObject.height);
     }
   },
 
   /**
    * Hide the history items list.
    */
-  hideItemList: function () {
+  hideItemList() {
     var itemList = document.getElementById("itemList");
     var expanderButton = document.getElementById("detailsExpander");
 
     if (!itemList.collapsed) {
       expanderButton.className = "expander-down";
       window.resizeBy(0, -itemList.boxObject.height);
       itemList.setAttribute("collapsed", "true");
     }
   },
 
   /**
    * Called by the item list expander button to toggle the list's visibility.
    */
-  toggleItemList: function ()
-  {
+  toggleItemList() {
     var itemList = document.getElementById("itemList");
 
     if (itemList.collapsed)
       this.showItemList();
     else
       this.hideItemList();
   }