Bug 1345253 - Use element.firstChild.remove() instead of element.removeChild(element.firstChild), r=jaws.

accessible/tests/browser/e10s/browser_caching_name.js

@@ -392,7 +392,7 @@ function* testSubtreeRule(browser, target, rule, expected) {
   yield ContentTask.spawn(browser, target.id, id => {
     let elm = content.document.getElementById(id);
     while (elm.firstChild) {
-      elm.removeChild(elm.firstChild);
+      elm.firstChild.remove();
     }
   });
   yield updateAccessibleIfNeeded(onEvent, target);

accessible/tests/browser/e10s/browser_treeupdate_doc.js

@@ -157,7 +157,7 @@ addAccessibleTask(`
   yield ContentTask.spawn(browser, {}, () => {
     // Remove HTML element.
     let docNode = content.document.getElementById('iframe').contentDocument;
-    docNode.removeChild(docNode.firstChild);
+    docNode.firstChild.remove();
   });
   let event = yield reorderEventPromise;
 
@@ -235,7 +235,7 @@ addAccessibleTask(`
     let docEl =
       content.document.getElementById('iframe').contentDocument.documentElement;
     // Remove aftermath of this test before next test starts.
-    docEl.removeChild(docEl.firstChild);
+    docEl.firstChild.remove();
   });
   // Make sure reorder event was fired and that the input was removed.
   yield reorderEventPromise;

accessible/tests/browser/e10s/browser_treeupdate_optgroup.js

@@ -56,7 +56,7 @@ addAccessibleTask('<select id="select"></select>', function*(browser, accDoc) {
   // Remove grouping from combobox
   yield ContentTask.spawn(browser, {}, () => {
     let contentSelect = content.document.getElementById('select');
-    contentSelect.removeChild(contentSelect.firstChild);
+    contentSelect.firstChild.remove();
   });
   yield onEvent;
 

accessible/tests/mochitest/events/test_mutation.html

@@ -414,8 +414,8 @@
         var l1 = doc.firstChild;
         this.target = l1.firstChild;
         var l2 = doc.lastChild;
-        l1.DOMNode.removeChild(l1.DOMNode.firstChild);
+        l1.DOMNode.firstChild.remove();
-        l2.DOMNode.removeChild(l2.DOMNode.firstChild);
+        l2.DOMNode.firstChild.remove();
       }
 
       this.check = function hideHideNDestroyDoc_check()

accessible/tests/mochitest/events/test_text.html

@@ -51,7 +51,7 @@
       this.invoke = function removeChildSpan_invoke()
       {
         // remove HTML span, a first child of the node
-        this.DOMNode.removeChild(this.DOMNode.firstChild);
+        this.DOMNode.firstChild.remove();
       }
 
       this.getID = function removeChildSpan_getID()
@@ -162,7 +162,7 @@
             this.DOMNode.removeChild(this.DOMNode.lastChild);
         } else {
           while (this.DOMNode.firstChild)
-            this.DOMNode.removeChild(this.DOMNode.firstChild);
+            this.DOMNode.firstChild.remove();
         }
       }
 

accessible/tests/mochitest/name/markup.js

@@ -316,7 +316,7 @@ function testNameForSubtreeRule(aElm, aRule)
   waitForEvent(EVENT_REORDER, aElm, gTestIterator.iterateNext, gTestIterator);
 
   while (aElm.firstChild)
-    aElm.removeChild(aElm.firstChild);
+    aElm.firstChild.remove();
 }
 
 /**

accessible/tests/mochitest/treeupdate/test_doc.html

@@ -266,7 +266,7 @@
 
         // Remove HTML element.
         var docNode = getDocNode(aID);
-        docNode.removeChild(docNode.firstChild);
+        docNode.firstChild.remove();
       }
 
       this.getID = function removeHTMLFromIFrameDoc_getID()

accessible/tests/mochitest/treeupdate/test_general.html

@@ -64,7 +64,7 @@
 
       this.invoke = function removeRemove_invoke()
       {
-        getNode(aContainer).removeChild(getNode(aContainer).firstChild);
+        getNode(aContainer).firstChild.remove();
       }
 
       this.finalCheck = function removeRemove_finalCheck()

accessible/tests/mochitest/treeupdate/test_optgroup.html

@@ -77,7 +77,7 @@
       this.invoke = function removeOptGroup_invoke()
       {
         this.option1Node = this.selectNode.firstChild.firstChild;
-        this.selectNode.removeChild(this.selectNode.firstChild);
+        this.selectNode.firstChild.remove();
       }
 
       this.eventSeq = [

browser/base/content/browser-ctrlTab.js

@@ -241,7 +241,7 @@ var ctrlTab = {
     aPreview._tab = aTab;
 
     if (aPreview.firstChild)
-      aPreview.removeChild(aPreview.firstChild);
+      aPreview.firstChild.remove();
     if (aTab) {
       let canvasWidth = this.canvasWidth;
       let canvasHeight = this.canvasHeight;

browser/base/content/browser-fxaccounts.js

@@ -330,7 +330,7 @@ var gFxAccounts = {
   populateSendTabToDevicesMenu(devicesPopup, url, title) {
     // remove existing menu items
     while (devicesPopup.hasChildNodes()) {
-      devicesPopup.removeChild(devicesPopup.firstChild);
+      devicesPopup.firstChild.remove();
     }
 
     const fragment = document.createDocumentFragment();

browser/base/content/browser-places.js

@@ -746,7 +746,7 @@ HistoryMenu.prototype = {
 
     // remove existing menu items
     while (undoPopup.hasChildNodes())
-      undoPopup.removeChild(undoPopup.firstChild);
+      undoPopup.firstChild.remove();
 
     // no restorable tabs, so make sure menu is disabled, and return
     if (this._getClosedTabCount() == 0) {
@@ -782,7 +782,7 @@ HistoryMenu.prototype = {
 
     // remove existing menu items
     while (undoPopup.hasChildNodes())
-      undoPopup.removeChild(undoPopup.firstChild);
+      undoPopup.firstChild.remove();
 
     // no restorable windows, so make sure menu is disabled, and return
     if (SessionStore.getClosedWindowCount() == 0) {

browser/base/content/pageinfo/pageInfo.js

@@ -418,7 +418,7 @@ function resetPageInfo(args) {
   /* Reset Feeds Tab */
   var feedListbox = document.getElementById("feedListbox");
   while (feedListbox.firstChild)
-    feedListbox.removeChild(feedListbox.firstChild);
+    feedListbox.firstChild.remove();
 
   /* Call registered overlay reset functions */
   onResetRegistry.forEach(function(func) { func(); });

browser/base/content/pageinfo/security.js

@@ -306,7 +306,7 @@ function setText(id, value) {
     element.value = value;
   else {
     if (element.hasChildNodes())
-      element.removeChild(element.firstChild);
+      element.firstChild.remove();
     var textNode = document.createTextNode(value);
     element.appendChild(textNode);
   }

browser/base/content/utilityOverlay.js

@@ -490,7 +490,7 @@ function createUserContextMenu(event, {
                                         useAccessKeys = true
                                       } = {}) {
   while (event.target.hasChildNodes()) {
-    event.target.removeChild(event.target.firstChild);
+    event.target.firstChild.remove();
   }
 
   let bundle = document.getElementById("bundle_browser");

browser/components/customizableui/CustomizableWidgets.jsm

@@ -244,12 +244,12 @@ const CustomizableWidgets = [
 
       let recentlyClosedTabs = doc.getElementById("PanelUI-recentlyClosedTabs");
       while (recentlyClosedTabs.firstChild) {
-        recentlyClosedTabs.removeChild(recentlyClosedTabs.firstChild);
+        recentlyClosedTabs.firstChild.remove();
       }
 
       let recentlyClosedWindows = doc.getElementById("PanelUI-recentlyClosedWindows");
       while (recentlyClosedWindows.firstChild) {
-        recentlyClosedWindows.removeChild(recentlyClosedWindows.firstChild);
+        recentlyClosedWindows.firstChild.remove();
       }
 
       let utils = RecentlyClosedTabsAndWindowsMenuUtils;

browser/components/customizableui/content/panelUI.js

@@ -492,7 +492,7 @@ const PanelUI = {
 
     // Remove all buttons from the view
     while (items.firstChild) {
-      items.removeChild(items.firstChild);
+      items.firstChild.remove();
     }
 
     // Add the current set of menuitems of the Help menu to this view

browser/components/feeds/FeedWriter.js

@@ -173,7 +173,7 @@ FeedWriter.prototype = {
     let element = this._document.getElementById(id);
     let textNode = text.createDocumentFragment(element);
     while (element.hasChildNodes())
-      element.removeChild(element.firstChild);
+      element.firstChild.remove();
     element.appendChild(textNode);
     if (text.base) {
       element.setAttributeNS(XML_NS, "base", text.base.spec);

browser/components/migration/content/migration.js

@@ -185,7 +185,7 @@ var MigrationWizard = { /* exported MigrationWizard */
 
     var profiles = document.getElementById("profiles");
     while (profiles.hasChildNodes())
-      profiles.removeChild(profiles.firstChild);
+      profiles.firstChild.remove();
 
     // Note that this block is still reached even if the user chose 'From File'
     // and we canceled the dialog.  When that happens, _migrator will be null.
@@ -225,7 +225,7 @@ var MigrationWizard = { /* exported MigrationWizard */
   onImportItemsPageShow() {
     var dataSources = document.getElementById("dataSources");
     while (dataSources.hasChildNodes())
-      dataSources.removeChild(dataSources.firstChild);
+      dataSources.firstChild.remove();
 
     var items = this._migrator.getMigrateData(this._selectedProfile, this._autoMigrate);
     for (var i = 0; i < 16; ++i) {
@@ -367,7 +367,7 @@ var MigrationWizard = { /* exported MigrationWizard */
   _listItems(aID) {
     var items = document.getElementById(aID);
     while (items.hasChildNodes())
-      items.removeChild(items.firstChild);
+      items.firstChild.remove();
 
     var itemID;
     for (var i = 0; i < 16; ++i) {

browser/components/places/content/browserPlacesViews.js

@@ -1011,7 +1011,7 @@ PlacesToolbar.prototype = {
 
     this._openedMenuButton = null;
     while (this._rootElt.hasChildNodes()) {
-      this._rootElt.removeChild(this._rootElt.firstChild);
+      this._rootElt.firstChild.remove();
     }
 
     let cc = this._resultNode.childCount;
@@ -1952,7 +1952,7 @@ PlacesPanelMenuView.prototype = {
 
     // Container is the toolbar itself.
     while (this._rootElt.hasChildNodes()) {
-      this._rootElt.removeChild(this._rootElt.firstChild);
+      this._rootElt.firstChild.remove();
     }
 
     for (let i = 0; i < this._resultNode.childCount; ++i) {

browser/components/places/content/places.js

@@ -419,7 +419,7 @@ var PlacesOrganizer = {
 
     // Remove existing menu items.  Last item is the restoreFromFile item.
     while (restorePopup.childNodes.length > 1)
-      restorePopup.removeChild(restorePopup.firstChild);
+      restorePopup.firstChild.remove();
 
     Task.spawn(function* () {
       let backupFiles = yield PlacesBackups.getBackupFiles();
@@ -1007,7 +1007,7 @@ var ViewMenu = {
       return endElement;
     }
     while (popup.hasChildNodes()) {
-      popup.removeChild(popup.firstChild);
+      popup.firstChild.remove();
     }
     return null;
   },

browser/components/preferences/blocklists.js

@@ -81,7 +81,7 @@ var gBlocklistManager = {
 
     let blocklistsText = document.getElementById("blocklistsText");
     while (blocklistsText.hasChildNodes()) {
-      blocklistsText.removeChild(blocklistsText.firstChild);
+      blocklistsText.firstChild.remove();
     }
     blocklistsText.appendChild(document.createTextNode(params.introText));
 

browser/components/preferences/in-content/advanced.js

@@ -557,7 +557,7 @@ var gAdvancedPane = {
 
     var list = document.getElementById("offlineAppsList");
     while (list.firstChild) {
-      list.removeChild(list.firstChild);
+      list.firstChild.remove();
     }
 
     var groups;

browser/components/preferences/languages.js

@@ -97,7 +97,7 @@ var gLanguagesDialog = {
   _buildAvailableLanguageList() {
     var availableLanguagesPopup = document.getElementById("availableLanguagesPopup");
     while (availableLanguagesPopup.hasChildNodes())
-      availableLanguagesPopup.removeChild(availableLanguagesPopup.firstChild);
+      availableLanguagesPopup.firstChild.remove();
 
     // Sort the list of languages by name
     this._availableLanguagesList.sort(function(a, b) {
@@ -119,7 +119,7 @@ var gLanguagesDialog = {
 
   readAcceptLanguages() {
     while (this._activeLanguages.hasChildNodes())
-      this._activeLanguages.removeChild(this._activeLanguages.firstChild);
+      this._activeLanguages.firstChild.remove();
 
     var selectedIndex = 0;
     var preference = document.getElementById("intl.accept_languages");

browser/components/preferences/permissions.js

@@ -218,7 +218,7 @@ var gPermissionManager = {
 
     var permissionsText = document.getElementById("permissionsText");
     while (permissionsText.hasChildNodes())
-      permissionsText.removeChild(permissionsText.firstChild);
+      permissionsText.firstChild.remove();
     permissionsText.appendChild(document.createTextNode(aParams.introText));
 
     document.title = aParams.windowTitle;

browser/components/syncedtabs/SyncedTabsDeckView.js

@@ -100,7 +100,7 @@ SyncedTabsDeckView.prototype = {
 
   _clearChilden() {
     while (this.container.firstChild) {
-      this.container.removeChild(this.container.firstChild);
+      this.container.firstChild.remove();
     }
   },
 

browser/components/syncedtabs/TabListView.js

@@ -169,7 +169,7 @@ TabListView.prototype = {
   _clearChilden(node) {
     let parent = node || this.container;
     while (parent.firstChild) {
-      parent.removeChild(parent.firstChild);
+      parent.firstChild.remove();
     }
   },
 

browser/components/uitour/UITour.jsm

@@ -1236,7 +1236,7 @@ this.UITour = {
       // Remove all the children of the notice (rating container
       // and the flex).
       while (notice.firstChild) {
-        notice.removeChild(notice.firstChild);
+        notice.firstChild.remove();
       }
 
       // Make sure that we have a valid URL. If we haven't, do not open the engagement page.

browser/extensions/pdfjs/content/web/viewer.js

@@ -3898,7 +3898,7 @@ var PDFAttachmentViewer = function PDFAttachmentViewerClosure() {
    this.attachments = null;
    var container = this.container;
    while (container.firstChild) {
-    container.removeChild(container.firstChild);
+    container.firstChild.remove();
    }
    if (!keepRenderedCapability) {
     this._renderedCapability = pdfjsLib.createPromiseCapability();
@@ -4598,7 +4598,7 @@ var PDFOutlineViewer = function PDFOutlineViewerClosure() {
    this.lastToggleIsShow = true;
    var container = this.container;
    while (container.firstChild) {
-    container.removeChild(container.firstChild);
+    container.firstChild.remove();
    }
   },
   _dispatchEvent: function PDFOutlineViewer_dispatchEvent(outlineCount) {

devtools/client/debugger/new/debugger.js

@@ -36082,7 +36082,7 @@ return /******/ (function(modules) { // webpackBootstrap
 	
 	function removeChildren(e) {
 	  for (var count = e.childNodes.length; count > 0; --count)
-	    { e.removeChild(e.firstChild) }
+	    { e.firstChild.remove() }
 	  return e
 	}
 	

devtools/client/framework/sidebar.js

@@ -576,7 +576,7 @@ ToolSidebar.prototype = {
     }
 
     while (this._tabbox.tabs && this._tabbox.tabs.hasChildNodes()) {
-      this._tabbox.tabs.removeChild(this._tabbox.tabs.firstChild);
+      this._tabbox.tabs.firstChild.remove();
     }
 
     if (this._currentTool && this._telemetry) {

devtools/client/inspector/markup/markup.js

@@ -1604,7 +1604,7 @@ MarkupView.prototype = {
       // this container will do double duty as the container for the single
       // text child.
       while (container.children.firstChild) {
-        container.children.removeChild(container.children.firstChild);
+        container.children.firstChild.remove();
       }
 
       container.setInlineTextChild(container.node.inlineTextChild);
@@ -1616,7 +1616,7 @@ MarkupView.prototype = {
 
     if (!container.hasChildren) {
       while (container.children.firstChild) {
-        container.children.removeChild(container.children.firstChild);
+        container.children.firstChild.remove();
       }
       container.childrenDirty = false;
       container.setExpanded(false);
@@ -1659,7 +1659,7 @@ MarkupView.prototype = {
         }
 
         while (container.children.firstChild) {
-          container.children.removeChild(container.children.firstChild);
+          container.children.firstChild.remove();
         }
 
         if (!(children.hasFirst && children.hasLast)) {

devtools/client/scratchpad/scratchpad.js

@@ -1367,7 +1367,7 @@ var Scratchpad = {
 
     recentFilesMenu.setAttribute("disabled", true);
     while (recentFilesPopup.hasChildNodes()) {
-      recentFilesPopup.removeChild(recentFilesPopup.firstChild);
+      recentFilesPopup.firstChild.remove();
     }
 
     if (filePaths.length > 0) {

devtools/client/shared/developer-toolbar.js

@@ -1019,7 +1019,7 @@ OutputPanel.prototype._update = function () {
 
   // Empty this._div
   while (this._div.hasChildNodes()) {
-    this._div.removeChild(this._div.firstChild);
+    this._div.firstChild.remove();
   }
 
   if (this.displayedOutput.data != null) {
@@ -1030,7 +1030,7 @@ OutputPanel.prototype._update = function () {
       }
 
       while (this._div.hasChildNodes()) {
-        this._div.removeChild(this._div.firstChild);
+        this._div.firstChild.remove();
       }
 
       let links = node.querySelectorAll("*[href]");

devtools/client/shared/widgets/TableWidget.js

@@ -1554,7 +1554,7 @@ Cell.prototype = {
       this.label.removeAttribute("value");
 
       while (this.label.firstChild) {
-        this.label.removeChild(this.label.firstChild);
+        this.label.firstChild.remove();
       }
 
       this.label.appendChild(value);

devtools/client/shared/widgets/tooltip/Tooltip.js

@@ -201,7 +201,7 @@ Tooltip.prototype = {
    */
   empty: function () {
     while (this.panel.hasChildNodes()) {
-      this.panel.removeChild(this.panel.firstChild);
+      this.panel.firstChild.remove();
     }
   },
 

devtools/client/styleeditor/StyleEditorUI.jsm

@@ -865,7 +865,7 @@ StyleEditorUI.prototype = {
       let list = details.querySelector(".stylesheet-media-list");
 
       while (list.firstChild) {
-        list.removeChild(list.firstChild);
+        list.firstChild.remove();
       }
 
       let rules = editor.mediaRules;

devtools/shared/gcli/commands/csscoverage.js

@@ -156,7 +156,7 @@ exports.items = [
         onback: () => {
           // The back button clears and hides .csscoverage-report
           while (host.hasChildNodes()) {
-            host.removeChild(host.firstChild);
+            host.firstChild.remove();
           }
           host.hidden = true;
         }

devtools/shared/gcli/source/lib/gcli/util/util.js

@@ -388,7 +388,7 @@ exports.createElement = function(doc, tag) {
  */
 exports.clearElement = function(elem) {
   while (elem.hasChildNodes()) {
-    elem.removeChild(elem.firstChild);
+    elem.firstChild.remove();
   }
 };
 

docshell/test/chrome/bug303267.html

@@ -13,7 +13,7 @@ function showpageshowcount()
 	var div1 = document.getElementById("div1");
 	while (div1.firstChild)
 	{
-		div1.removeChild(div1.firstChild);
+		div1.firstChild.remove();
 	}
 	div1.appendChild(document.createTextNode(
 	  "pageshowcount: " + pageshowcount));

docshell/test/navigation/file_bug534178.html

@@ -3,7 +3,7 @@
     <script>
     
       function testDone() {
-        document.body.removeChild(document.body.firstChild);
+        document.body.firstChild.remove();
         var isOK = false;
         try {
           isOK = history.previous != location;

docshell/test/test_bug570341.html

@@ -31,7 +31,7 @@ https://bugzilla.mozilla.org/show_bug.cgi?id=570341
 
   function showSequence(node){
     while(node.firstChild) {
-      node.removeChild(node.firstChild);
+      node.firstChild.remove();
     }
     var sequence = [];
     for (var p in moments) {

dom/base/crashtests/771639.html

@@ -1,7 +1,7 @@
 <!DOCTYPE html>
 <script>
 var root = document.documentElement;
-while(root.firstChild) { root.removeChild(root.firstChild); }
+while(root.firstChild) { root.firstChild.remove(); }
 var div = document.createElement("div");
 root.appendChild(div);
 

dom/base/test/test_bug416383.html

@@ -26,7 +26,7 @@ function runTest() {
   ok(attrs != null, "Element should have attributes!");
   var attr = testParent.firstChild.getAttributeNode("someattr");
   ok(attr.value == "foo", "The value of the attribute should be 'foo'!");
-  testParent.removeChild(testParent.firstChild);
+  testParent.firstChild.remove();
   SpecialPowers.gc();
   ok(true, "Browser should not crash!")
 

dom/base/test/test_mutationobservers.html

@@ -246,7 +246,7 @@ function testChildList() {
       m = null;
     });
   m.observe(div, { childList: true});
-  div.removeChild(div.firstChild);
+  div.firstChild.remove();
 }
 
 function testChildList2() {

dom/html/crashtests/453406-1.html

@@ -5,7 +5,7 @@ function boom()
 {
   var r = document.documentElement;
   while (r.firstChild)
-    r.removeChild(r.firstChild);
+    r.firstChild.remove();
 
   var b    = document.createElement("BODY");
   var s    = document.createElement("SCRIPT");

dom/html/crashtests/564461.xhtml

@@ -11,7 +11,7 @@
 
 function boom()
 {
-  while (document.documentElement.firstChild) document.documentElement.removeChild(document.documentElement.firstChild);
+  while (document.documentElement.firstChild) document.documentElement.firstChild.remove();
   
   document.addEventListener("DOMSubtreeModified", function(){});
   document.addEventListener("DOMNodeInsertedIntoDocument", function(){});

dom/html/test/forms/test_form_attribute-1.html

@@ -424,7 +424,7 @@ for (var name of elementNames) {
   for (var func of functions) {
     // Clean-up.
     while (content.firstChild) {
-      content.removeChild(content.firstChild);
+      content.firstChild.remove();
     }
     for (form of forms) {
       content.appendChild(form);

dom/html/test/test_bug300691-1.html

@@ -95,7 +95,7 @@ valueIs("abcdeTesth",
         "Modifying textnode text shouldn't affect value in edited textarea");
 defValueIs("abcdefghlmno", "Modified textnode text 3");
 
-t.removeChild(t.firstChild);
+t.firstChild.remove();
 valueIs("abcdeTesth",
         "Removing child textnode shouldn't affect value in edited textarea");
 defValueIs("defghlmno", "Removed textnode 3");

dom/html/test/test_bug311681.html

@@ -78,7 +78,7 @@ https://bugzilla.mozilla.org/show_bug.cgi?id=311681
 
   function clear(node) {
     while (node.hasChildNodes()) {
-      node.removeChild(node.firstChild);
+      node.firstChild.remove();
     }
   }
 

dom/html/test/test_bug311681.xhtml

@@ -78,7 +78,7 @@ https://bugzilla.mozilla.org/show_bug.cgi?id=311681
 
   function clear(node) {
     while (node.hasChildNodes()) {
-      node.removeChild(node.firstChild);
+      node.firstChild.remove();
     }
   }
 

dom/html/test/test_bug691.html

@@ -23,7 +23,7 @@ function remove() {
   var stage = document.getElementById("stage");
   var body = document.getElementsByTagName("BODY")[0];
   while (stage.firstChild) {
-    stage.removeChild(stage.firstChild);
+    stage.firstChild.remove();
   }
 }
 

dom/media/test/manifest.js

@@ -1545,7 +1545,7 @@ function removeNodeAndSource(n) {
   n.srcObject = null;
   n.src = "";
   while (n.firstChild) {
-    n.removeChild(n.firstChild);
+    n.firstChild.remove();
   }
 }
 

dom/media/webvtt/vtt.jsm

@@ -889,7 +889,7 @@ Cu.import('resource://gre/modules/Services.jsm');
 
     // Remove all previous children.
     while (overlay.firstChild) {
-      overlay.removeChild(overlay.firstChild);
+      overlay.firstChild.remove();
     }
 
     var controlBar;

dom/smil/test/test_smilChangeAfterFrozen.xhtml

@@ -188,7 +188,7 @@ function testCurrentColorChange()
 
   // Clean up
   gCircle.removeAttribute("color");
-  gCircle.removeChild(gCircle.firstChild);
+  gCircle.firstChild.remove();
 }
 
 function testCurrentColorChangeUsingStyle()
@@ -209,7 +209,7 @@ function testCurrentColorChangeUsingStyle()
 
   // Clean up
   gCircle.removeAttribute("style");
-  gCircle.removeChild(gCircle.firstChild);
+  gCircle.firstChild.remove();
 }
 
 function getFallbackColor(pServerStr)
@@ -236,7 +236,7 @@ function testCurrentColorChangeOnFallback()
      "Checking animated fallback fill=currentColor after updating context");
 
   gCircle.removeAttribute("style");
-  gCircle.removeChild(gCircle.firstChild);
+  gCircle.firstChild.remove();
 }
 
 function testInheritChange()
@@ -255,7 +255,7 @@ function testInheritChange()
      "Checking animated fill=inherit after updating context");
 
   gCircleParent.removeAttribute("fill");
-  gCircle.removeChild(gCircle.firstChild);
+  gCircle.firstChild.remove();
 }
 
 function testInheritChangeUsingStyle()
@@ -275,7 +275,7 @@ function testInheritChangeUsingStyle()
      + "(using style attr)");
 
   gCircleParent.removeAttribute("style");
-  gCircle.removeChild(gCircle.firstChild);
+  gCircle.firstChild.remove();
 }
 
 function testEmUnitChangeOnProp()
@@ -294,7 +294,7 @@ function testEmUnitChangeOnProp()
      "Checking animated font-size=2em after updating context");
 
   gCircleParent.removeAttribute("font-size");
-  gCircle.removeChild(gCircle.firstChild);
+  gCircle.firstChild.remove();
 }
 
 function testEmUnitChangeOnPropBase()
@@ -319,7 +319,7 @@ function testEmUnitChangeOnPropBase()
      "Checking animated font-size=30px after updating context");
 
   gCircleParent.removeAttribute("font-size");
-  gCircle.removeChild(gCircle.firstChild);
+  gCircle.firstChild.remove();
 }
 
 function testEmUnitChangeOnLength()
@@ -344,7 +344,7 @@ function testEmUnitChangeOnLength()
      "resampling");
 
   gCircleParent.removeAttribute("font-size");
-  gCircle.removeChild(gCircle.firstChild);
+  gCircle.firstChild.remove();
 }
 
 function testPercentUnitChangeOnProp()
@@ -363,7 +363,7 @@ function testPercentUnitChangeOnProp()
      "Checking animated font-size=150% after updating context");
 
   gCircleParent.removeAttribute("font-size");
-  gCircle.removeChild(gCircle.firstChild);
+  gCircle.firstChild.remove();
 }
 
 function testPercentUnitChangeOnLength()
@@ -399,7 +399,7 @@ function testPercentUnitChangeOnLength()
      "Checking animated length=100% after updating context");
 
   gSvg.setAttribute("height", oldHeight);
-  gCircle.removeChild(gCircle.firstChild);
+  gCircle.firstChild.remove();
 }
 
 function testRelativeFontSize()
@@ -421,7 +421,7 @@ function testRelativeFontSize()
   ok(fsize > 20, "Checking animated font-size > 20px after updating context");
 
   gCircleParent.removeAttribute("font-size");
-  gCircle.removeChild(gCircle.firstChild);
+  gCircle.firstChild.remove();
 }
 
 function testRelativeFontWeight()
@@ -447,7 +447,7 @@ function testRelativeFontWeight()
      "Checking animated font-weight = 900 after updating context");
 
   gCircleParent.removeAttribute("font-weight");
-  gCircle.removeChild(gCircle.firstChild);
+  gCircle.firstChild.remove();
 }
 
 function testRelativeFont()
@@ -479,7 +479,7 @@ function testRelativeFont()
      "Checking size of shorthand 'font' > 20px after updating context");
 
   gCircleParent.removeAttribute("font-size");
-  gCircle.removeChild(gCircle.firstChild);
+  gCircle.firstChild.remove();
 }
 
 function testCalcFontSize()
@@ -500,7 +500,7 @@ function testCalcFontSize()
                 "context");
 
   gCircleParent.removeAttribute("font-size");
-  gCircle.removeChild(gCircle.firstChild);
+  gCircle.firstChild.remove();
 }
 
 function testDashArray()
@@ -529,7 +529,7 @@ function testDashArray()
 
   gSvg.setAttribute("height", oldHeight);
   gSvg.setAttribute("width",  oldWidth);
-  gCircle.removeChild(gCircle.firstChild);
+  gCircle.firstChild.remove();
 }
 
 function testClip()

dom/svg/test/test_SVGTransformListAddition.xhtml

@@ -153,7 +153,7 @@ function runAdditionTestCase(test, elem, svg)
   // We assume the only children of elem are the animation elements we've just
   // added.
   while (elem.firstChild) {
-    elem.removeChild(elem.firstChild);
+    elem.firstChild.remove();
   }
 }
 

dom/svg/test/test_text_dirty.html

@@ -28,7 +28,7 @@ function runTest() {
 
   // Dirty the frames.
   document.getElementById("display").style.width = "700px";
-  svgText.removeChild(svgText.firstChild);
+  svgText.firstChild.remove();
 
   // Paint without flushing layout.  If the test fails, we'll trigger
   // an assertion.

dom/svg/test/test_text_update.html

@@ -25,7 +25,7 @@ ok(length > 0, "text.getComputedTextLength() > 0");
 text.firstChild.nodeValue += "cd";
 ok(text.getComputedTextLength() > length, "text.getComputedTextLength() changes directly after DOM mutation");
 
-text.removeChild(text.firstChild);
+text.firstChild.remove();
 is(text.getComputedTextLength(), 0, "text.getComputedTextLength() == 0 after removing child");
 </script>
 </pre>

dom/tests/mochitest/webcomponents/test_shadow_element.html

@@ -90,7 +90,7 @@ ok(firstDistNodes[0].id == "one" &&
    firstDistNodes[3].id == "four", "Reprojection through shadow should preserve node order.");
 
 // Remove a node from the host and make sure that it is removed from all insertion points.
-host.removeChild(host.firstChild);
+host.firstChild.remove();
 firstDistNodes = firstContent.getDistributedNodes();
 secondDistNodes = secondContent.getDistributedNodes();
 
@@ -115,7 +115,7 @@ firstShadow.appendChild(shadowChild);
 is(firstContent.getDistributedNodes()[0], shadowChild, "Elements in shadow insertioin point should be projected into content insertion points.");
 
 // Remove child of ShadowRoot and check that projected node is removed from insertion point.
-firstShadow.removeChild(firstShadow.firstChild);
+firstShadow.firstChild.remove();
 
 is(firstContent.getDistributedNodes().length, 0, "Reprojected element was removed from ShadowRoot, thus it should be removed from content insertion point.");
 
@@ -135,7 +135,7 @@ host.innerHTML = '<span></span>';
 is(firstContent.getDistributedNodes()[0], host.firstChild, "Child of host should be projected to insertion point.");
 
 // Remove node and make sure that it is removed from distributed nodes.
-host.removeChild(host.firstChild);
+host.firstChild.remove();
 
 is(firstContent.getDistributedNodes().length, 0, "Node removed from host should be removed from insertion point.");
 

dom/xslt/tests/mochitest/test_bug319374.xhtml

@@ -45,7 +45,7 @@ https://bugzilla.mozilla.org/show_bug.cgi?id=319374
       while (res = result.iterateNext()) {
         ++counter; 
         var anon = getAnonymousNodes(res);
-        anon[0].removeChild(anon[0].firstChild); // Removing a child node
+        anon[0].firstChild.remove(); // Removing a child node
         anon[0].removeAttribute("attr1"); // Removing an attribute
         anon[1].firstChild.data = "anon text changed" // Modifying text data
       }

dom/xul/templates/tests/chrome/test_sortservice.xul

@@ -56,7 +56,7 @@ function doTests()
     is(actual, test[2], "sorted step " + (t + 1));
 
     while(box.hasChildNodes())
-      box.removeChild(box.firstChild);
+      box.firstChild.remove();
     box.removeAttribute("sortDirection");
   }
 

dom/xul/test/test_bug311681.xul

@@ -81,7 +81,7 @@ https://bugzilla.mozilla.org/show_bug.cgi?id=311681
 
   function clear(node) {
     while (node.hasChildNodes()) {
-      node.removeChild(node.firstChild);
+      node.firstChild.remove();
     }
   }
 

editor/composer/crashtests/407062-1.html

@@ -7,7 +7,7 @@ function boom()
 {
   var r = document.documentElement;
   while(r.firstChild)
-    r.removeChild(r.firstChild);
+    r.firstChild.remove();
 
   document.execCommand("contentReadOnly", false, "");
   document.documentElement.focus();

editor/libeditor/crashtests/1317718.html

@@ -4,7 +4,7 @@
 addEventListener('DOMContentLoaded', function() {
   let root = document.documentElement;
   while(root.firstChild) {
-    root.removeChild(root.firstChild);
+    root.firstChild.remove();
   }
   document.designMode = 'on';
   document.removeChild(document.documentElement);

editor/libeditor/crashtests/1324505.html

@@ -4,7 +4,7 @@
 addEventListener("DOMContentLoaded", function(){
   let root = document.documentElement;
   while(root.firstChild) {
-    root.removeChild(root.firstChild);
+    root.firstChild.remove();
   }
   let o_0 = document.createElement("body");
   root.appendChild(o_0);

editor/libeditor/crashtests/612565-1.html

@@ -10,7 +10,7 @@
       doc.body.appendChild(doc.createTextNode("foo"));
       doc.designMode = "on";
       while (doc.body.firstChild) {
-        doc.body.removeChild(doc.body.firstChild);
+        doc.body.firstChild.remove();
       }
     };
   </script>

editor/libeditor/crashtests/713427-2.xhtml

@@ -6,7 +6,7 @@
 function boom()
 {
   while (document.documentElement.firstChild) {
-    document.documentElement.removeChild(document.documentElement.firstChild);
+    document.documentElement.firstChild.remove();
   }
 
   var td = document.createElementNS("http://www.w3.org/1999/xhtml", "td");

editor/libeditor/crashtests/761861.html

@@ -3,7 +3,7 @@
 function boom() {
   var r = document.documentElement;
   while (r.firstChild) {
-    r.removeChild(r.firstChild);
+    r.firstChild.remove();
   }
 
   document.documentElement.contentEditable = "true";

editor/libeditor/crashtests/766413.html

@@ -7,7 +7,7 @@ function boom()
 {
   var root = document.documentElement;
   while (root.firstChild) {
-    root.removeChild(root.firstChild);
+    root.firstChild.remove();
   }
 
   var space = document.createTextNode(" ");

editor/libeditor/crashtests/767169.html

@@ -7,7 +7,7 @@
 function boom()
 {
   var root = document.documentElement;
-  while (root.firstChild) { root.removeChild(root.firstChild); }
+  while (root.firstChild) { root.firstChild.remove(); }
   root.contentEditable = "true";
   document.removeChild(root);
   document.appendChild(root);

editor/libeditor/crashtests/768765.html

@@ -7,7 +7,7 @@ function boom()
 {
   var root = document.documentElement;
 
-  while (root.firstChild) { root.removeChild(root.firstChild); }
+  while (root.firstChild) { root.firstChild.remove(); }
 
   var body = document.createElementNS("http://www.w3.org/1999/xhtml", "body");
   var div = document.createElementNS("http://www.w3.org/1999/xhtml", "div");

editor/libeditor/crashtests/772282.html

@@ -6,7 +6,7 @@
 function boom()
 {
   var root = document.documentElement;
-  while(root.firstChild) { root.removeChild(root.firstChild); }
+  while(root.firstChild) { root.firstChild.remove(); }
   var body = document.createElementNS("http://www.w3.org/1999/xhtml", "body");
   body.setAttributeNS(null, "contenteditable", "true");
   var img = document.createElementNS("http://www.w3.org/1999/xhtml", "img");

editor/libeditor/tests/browserscope/lib/richtext2/richtext2/static/js/range.js

@@ -2109,7 +2109,7 @@ goog.dom.createTable_ = function(doc, rows, columns, fillWithNbsp) {
   totalHtml.push("</table>");
   var elem = doc.createElement(goog.dom.TagName.DIV);
   elem.innerHTML = totalHtml.join("");
-  return elem.removeChild(elem.firstChild)
+  return elem.firstChild.remove()
 };
 goog.dom.htmlToDocumentFragment = function(htmlString) {
   return goog.dom.htmlToDocumentFragment_(document, htmlString)
@@ -2118,12 +2118,12 @@ goog.dom.htmlToDocumentFragment_ = function(doc, htmlString) {
   var tempDiv = doc.createElement("div");
   if(goog.dom.BrowserFeature.INNER_HTML_NEEDS_SCOPED_ELEMENT) {
     tempDiv.innerHTML = "<br>" + htmlString;
-    tempDiv.removeChild(tempDiv.firstChild)
+    tempDiv.firstChild.remove()
   }else {
     tempDiv.innerHTML = htmlString
   }
   if(tempDiv.childNodes.length == 1) {
-    return tempDiv.removeChild(tempDiv.firstChild)
+    return tempDiv.firstChild.remove()
   }else {
     var fragment = doc.createDocumentFragment();
     while(tempDiv.firstChild) {

editor/libeditor/tests/file_select_all_without_body.html

@@ -16,7 +16,7 @@ function boom()
 {
   var root = document.documentElement;
   while(root.firstChild) {
-    root.removeChild(root.firstChild);
+    root.firstChild.remove();
   }
   root.appendChild(document.createTextNode("Mozilla"));
   root.focus();

editor/libeditor/tests/test_bug612447.html

@@ -44,7 +44,7 @@ SimpleTest.waitForFocus(function() {
   var beforeB = snapshotWindow(win, true);
   is(b.textContent, "X", "Typing should work");
   while (b.firstChild) {
-    b.removeChild(b.firstChild);
+    b.firstChild.remove();
   }
   ok(editorCommandsEnabled(), "The editor commands should work");
 
@@ -58,7 +58,7 @@ SimpleTest.waitForFocus(function() {
   var afterB = snapshotWindow(win, true);
   is(b.textContent, "X", "Typing should work");
   while (b.firstChild) {
-    b.removeChild(b.firstChild);
+    b.firstChild.remove();
   }
   ok(editorCommandsEnabled(), "The editor commands should work");
 

gfx/tests/crashtests/595727-1.html

@@ -6,7 +6,7 @@
 function doTest()
 {
   var r = document.documentElement;
-  while(r.firstChild) { r.removeChild(r.firstChild); }
+  while(r.firstChild) { r.firstChild.remove(); }
   var body = document.createElementNS("http://www.w3.org/1999/xhtml", "body"); 
   r.appendChild(body); 
   body.contentEditable = "true"; 

layout/base/crashtests/372550-1.html

@@ -11,7 +11,7 @@
   document.body.offsetWidth;
   var div = document.getElementById("x");
   div.id = "y";
-  div.removeChild(div.firstChild);
+  div.firstChild.remove();
 </script>
 </body>
 </html>

layout/base/crashtests/393661-1.html

@@ -7,7 +7,7 @@
 function boom()
 {
   var z = document.getElementById("z");
-  z.removeChild(z.firstChild);
+  z.firstChild.remove();
 }
 </script>
 </head>

layout/base/crashtests/403175-1.html

@@ -9,7 +9,7 @@ function boom()
   ++i;
   
   while (document.body.firstChild)
-    document.body.removeChild(document.body.firstChild);
+    document.body.firstChild.remove();
 
   var table = document.createElement("table");
   document.body.appendChild(table);

layout/base/crashtests/468578-1.xhtml

@@ -8,7 +8,7 @@ function boom()
   var legend = document.getElementById("legend");
   legend.appendChild(document.createTextNode("T"));
   document.documentElement.offsetHeight;
-  legend.removeChild(legend.firstChild);
+  legend.firstChild.remove();
   document.body.removeChild(legend);
 }
 

layout/base/crashtests/538267-1.html

@@ -8,7 +8,7 @@ div { -moz-column-count: 2; width: 0; }
 function boom()
 {
   var v = document.getElementById("v");
-  v.removeChild(v.firstChild);
+  v.firstChild.remove();
 }
 </script>
 </head>

layout/base/crashtests/852293.html

@@ -57,7 +57,7 @@ function bounceDE()
 
 function clearChildren(root)
 {
-  while(root.firstChild) { root.removeChild(root.firstChild); }
+  while(root.firstChild) { root.firstChild.remove(); }
 }
 
 </script>

layout/base/crashtests/898913.html

@@ -13,7 +13,7 @@ div:first-letter { float: right; }
 function boom()
 {
   var d = document.getElementById('d');
-  d.removeChild(d.firstChild);
+  d.firstChild.remove();
 }
 
 </script>

layout/generic/crashtests/413085-1.html

@@ -10,7 +10,7 @@ body:first-letter { float: right; }
 
 function boom()
 {
-  document.body.removeChild(document.body.firstChild);
+  document.body.firstChild.remove();
   document.body.appendChild(document.createTextNode('x'));  
 }
 

layout/generic/crashtests/413085-2.html

@@ -5,7 +5,7 @@
 </style>
 <script>
   function boom() {
-   document.body.removeChild(document.body.firstChild);
+   document.body.firstChild.remove();
   }
 </script>
 </head>

layout/generic/crashtests/426040-1.html

@@ -12,7 +12,7 @@ div { height: 1px; }
 function boom()
 {
   var a = document.getElementById("a"); 
-  a.removeChild(a.firstChild);
+  a.firstChild.remove();
   document.documentElement.style.outline = "none";
 }
 

layout/generic/crashtests/472776-1.html

@@ -9,7 +9,7 @@ function boom()
   v.childNodes[1].firstChild.data = "";
   document.documentElement.offsetHeight;
   v.appendChild(document.createTextNode("D"));
-  v.removeChild(v.firstChild);
+  v.firstChild.remove();
 }
 
 </script>

layout/generic/crashtests/603490-1.html

@@ -3,7 +3,7 @@
 function boom()
 {
   while (document.documentElement.firstChild)
-    document.documentElement.removeChild(document.documentElement.firstChild);
+    document.documentElement.firstChild.remove();
   document.documentElement.contentEditable = "true";
   document.execCommand("strikethrough", false, null);
   try { document.execCommand("justifyfull", false, null); } catch(e) { }

layout/generic/crashtests/603510-1.html

@@ -6,7 +6,7 @@ function boom()
   var r = document.documentElement;
 
   while (r.firstChild)
-    r.removeChild(r.firstChild);
+    r.firstChild.remove();
 
   var a = document.createTextNode("a");
   r.appendChild(a);

layout/generic/crashtests/667025.html

@@ -11,7 +11,7 @@ function boom()
   document.documentElement.offsetHeight;
   var s = document.getElementById("s");
 
-  s.removeChild(s.firstChild);
+  s.firstChild.remove();
 
   document.documentElement.offsetHeight;
 }

layout/generic/crashtests/868906.html

@@ -7,7 +7,7 @@
 function boom()
 {
   var root = document.documentElement;
-  while(root.firstChild) { root.removeChild(root.firstChild); }
+  while(root.firstChild) { root.firstChild.remove(); }
   root.appendChild(document.createElement("body"));
   root.offsetHeight;
 

layout/reftests/bidi/730562-1.html

@@ -11,7 +11,7 @@ function boom()
 
   // A dynamic change
   var x = document.getElementById("x");
-  x.removeChild(x.firstChild);
+  x.firstChild.remove();
   x.appendChild(document.createTextNode("\n\n\n"));
 }
 

layout/reftests/bugs/306660-3.html

@@ -4,7 +4,7 @@
 <script>
   function loaded() {
     var f = document.getElementById("x");
-    f.removeChild(f.firstChild);
+    f.firstChild.remove();
   }
 </script>
 </head>

layout/reftests/bugs/398682-1.html

@@ -37,7 +37,7 @@ function bounce()
     var docElemChildren = [];
     while (docElem.firstChild) {
         docElemChildren.push(docElem.firstChild);
-        docElem.removeChild(docElem.firstChild);
+        docElem.firstChild.remove();
     }
 
     for (var i = 0; i < docElemChildren.length; ++i)

layout/reftests/bugs/418766-1a.html

@@ -4,7 +4,7 @@
 function boom()
 {
   var n = document.getElementById("editMe");
-  n.removeChild(n.firstChild);
+  n.firstChild.remove();
   document.documentElement.className = "";
 }
 </script>

layout/reftests/bugs/421239-1.html

@@ -8,7 +8,7 @@
   function boom()
   {
     var a = document.getElementById("a");
-    a.removeChild(a.firstChild);
+    a.firstChild.remove();
     document.documentElement.className = "";
   }
   </script>

layout/reftests/bugs/421239-2.html

@@ -8,7 +8,7 @@
   function boom()
   {
     var a = document.getElementById("a");
-    a.removeChild(a.firstChild);
+    a.firstChild.remove();
     document.documentElement.className = "";
   }
   </script>

layout/reftests/bugs/496840-1.html

@@ -12,7 +12,7 @@ l.textContent = "#1";
 fs1.insertBefore(l, fs1.firstChild);
 
 var fs2 = document.getElementById("fs2");
-fs2.removeChild(fs2.firstChild);
+fs2.firstChild.remove();
 </script>
 </body>
 </html>

layout/reftests/forms/textarea/setvalue-framereconstruction-1.html

@@ -22,7 +22,7 @@ function boom()
   document.getElementById("div").style.MozBinding = "url('#foo')";
 
   var opt1 = document.getElementById("opt1");
-  opt1.removeChild(opt1.firstChild);
+  opt1.firstChild.remove();
 
   document.getElementById("textarea").value += " y";
 

layout/reftests/table-anonymous-boxes/277995-1.html

@@ -4,7 +4,7 @@
   <script type="text/javascript" language="javascript">
     function doMore(data) {
       while(data.hasChildNodes()) 
-        data.removeChild(data.firstChild);
+        data.firstChild.remove();
       for (var i = 0; i < 10; i++) {
 	append(data);
       }