Bug 1402941 - Add HTMLSlotElement

Tag #1375

14 files changed, 453 insertions, 294 deletions

diff --git a/dom/base/nsGkAtomList.h b/dom/base/nsGkAtomList.h
index 0ae35480f..35963afd7 100644
--- a/dom/base/nsGkAtomList.h
+++ b/dom/base/nsGkAtomList.h
@@ -1564,6 +1564,7 @@ GK_ATOM(shape_rendering, "shape-rendering")
 GK_ATOM(skewX, "skewX")
 GK_ATOM(skewY, "skewY")
 GK_ATOM(slope, "slope")
+GK_ATOM(slot, "slot")
 GK_ATOM(softLight, "soft-light")
 GK_ATOM(spacing, "spacing")
 GK_ATOM(spacingAndGlyphs, "spacingAndGlyphs")
diff --git a/dom/html/HTMLSlotElement.cpp b/dom/html/HTMLSlotElement.cpp
new file mode 100644
index 000000000..9f24f8ba3
--- /dev/null
+++ b/dom/html/HTMLSlotElement.cpp
@@ -0,0 +1,67 @@
+/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
+/* vim: set ts=8 sts=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/. */
+
+#include "mozilla/dom/HTMLSlotElement.h"
+#include "mozilla/dom/HTMLSlotElementBinding.h"
+#include "mozilla/dom/HTMLUnknownElement.h"
+#include "nsGkAtoms.h"
+#include "nsDocument.h"
+
+nsGenericHTMLElement*
+NS_NewHTMLSlotElement(already_AddRefed<mozilla::dom::NodeInfo>&& aNodeInfo,
+                      mozilla::dom::FromParser aFromParser)
+{
+  RefPtr<mozilla::dom::NodeInfo> nodeInfo(aNodeInfo);
+  /* Disabled for now
+  if (nsDocument::IsWebComponentsEnabled(nodeInfo)) {
+    already_AddRefed<mozilla::dom::NodeInfo> nodeInfoArg(nodeInfo.forget());
+    return new mozilla::dom::HTMLSlotElement(nodeInfoArg);
+  }
+  */
+
+  already_AddRefed<mozilla::dom::NodeInfo> nodeInfoArg(nodeInfo.forget());
+  return new mozilla::dom::HTMLUnknownElement(nodeInfoArg);
+}
+
+namespace mozilla {
+namespace dom {
+
+HTMLSlotElement::HTMLSlotElement(already_AddRefed<mozilla::dom::NodeInfo>& aNodeInfo)
+  : nsGenericHTMLElement(aNodeInfo)
+{
+}
+
+HTMLSlotElement::~HTMLSlotElement()
+{
+}
+
+NS_IMPL_ADDREF_INHERITED(HTMLSlotElement, nsGenericHTMLElement)
+NS_IMPL_RELEASE_INHERITED(HTMLSlotElement, nsGenericHTMLElement)
+
+NS_IMPL_CYCLE_COLLECTION_INHERITED(HTMLSlotElement,
+                                   nsGenericHTMLElement,
+                                   mAssignedNodes)
+
+NS_INTERFACE_MAP_BEGIN_CYCLE_COLLECTION(HTMLSlotElement)
+NS_INTERFACE_MAP_END_INHERITING(nsGenericHTMLElement)
+
+NS_IMPL_ELEMENT_CLONE(HTMLSlotElement)
+
+void
+HTMLSlotElement::AssignedNodes(const AssignedNodesOptions& aOptions,
+                               nsTArray<RefPtr<nsINode>>& aNodes)
+{
+  aNodes = mAssignedNodes;
+}
+
+JSObject*
+HTMLSlotElement::WrapNode(JSContext* aCx, JS::Handle<JSObject*> aGivenProto)
+{
+  return HTMLSlotElementBinding::Wrap(aCx, this, aGivenProto);
+}
+
+} // namespace dom
+} // namespace mozilla
diff --git a/dom/html/HTMLSlotElement.h b/dom/html/HTMLSlotElement.h
new file mode 100644
index 000000000..187a295db
--- /dev/null
+++ b/dom/html/HTMLSlotElement.h
@@ -0,0 +1,53 @@
+/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
+/* vim: set ts=8 sts=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/. */
+
+#ifndef mozilla_dom_HTMLSlotElement_h
+#define mozilla_dom_HTMLSlotElement_h
+
+#include "nsIDOMHTMLElement.h"
+#include "nsGenericHTMLElement.h"
+#include "nsTArray.h"
+
+namespace mozilla {
+namespace dom {
+
+struct AssignedNodesOptions;
+
+class HTMLSlotElement final : public nsGenericHTMLElement
+{
+public:
+  explicit HTMLSlotElement(already_AddRefed<mozilla::dom::NodeInfo>& aNodeInfo);
+  NS_IMPL_FROMCONTENT_HTML_WITH_TAG(HTMLSlotElement, slot)
+
+  NS_DECL_ISUPPORTS_INHERITED
+  NS_DECL_CYCLE_COLLECTION_CLASS_INHERITED(HTMLSlotElement, nsGenericHTMLElement)
+  virtual nsresult Clone(mozilla::dom::NodeInfo* aNodeInfo, nsINode** aResult) const override;
+
+  void SetName(const nsAString& aName, ErrorResult& aRv)
+  {
+    SetHTMLAttr(nsGkAtoms::name, aName, aRv);
+  }
+
+  void GetName(nsAString& aName)
+  {
+    GetHTMLAttr(nsGkAtoms::name, aName);
+  }
+
+  void AssignedNodes(const AssignedNodesOptions& aOptions,
+                     nsTArray<RefPtr<nsINode>>& aNodes);
+
+protected:
+  virtual ~HTMLSlotElement();
+  virtual JSObject*
+  WrapNode(JSContext* aCx, JS::Handle<JSObject*> aGivenProto) override;
+
+  nsTArray<RefPtr<nsINode>> mAssignedNodes;
+};
+
+} // namespace dom
+} // namespace mozilla
+
+#endif // mozilla_dom_HTMLSlotElement_h
diff --git a/dom/html/moz.build b/dom/html/moz.build
index 1ccc630fd..79554df21 100644
--- a/dom/html/moz.build
+++ b/dom/html/moz.build
@@ -95,6 +95,7 @@ EXPORTS.mozilla.dom += [
     'HTMLSharedElement.h',
     'HTMLSharedListElement.h',
     'HTMLSharedObjectElement.h',
+    'HTMLSlotElement.h',
     'HTMLSourceElement.h',
     'HTMLSpanElement.h',
     'HTMLStyleElement.h',
@@ -174,6 +175,7 @@ UNIFIED_SOURCES += [
     'HTMLSharedElement.cpp',
     'HTMLSharedListElement.cpp',
     'HTMLSharedObjectElement.cpp',
+    'HTMLSlotElement.cpp',
     'HTMLSourceElement.cpp',
     'HTMLSpanElement.cpp',
     'HTMLStyleElement.cpp',
diff --git a/dom/html/nsGenericHTMLElement.h b/dom/html/nsGenericHTMLElement.h
index 3b451b29c..1b0977fa2 100644
--- a/dom/html/nsGenericHTMLElement.h
+++ b/dom/html/nsGenericHTMLElement.h
@@ -1700,6 +1700,7 @@ NS_DECLARE_NS_NEW_HTML_ELEMENT(Pre)
 NS_DECLARE_NS_NEW_HTML_ELEMENT(Progress)
 NS_DECLARE_NS_NEW_HTML_ELEMENT(Script)
 NS_DECLARE_NS_NEW_HTML_ELEMENT(Select)
+NS_DECLARE_NS_NEW_HTML_ELEMENT(Slot)
 NS_DECLARE_NS_NEW_HTML_ELEMENT(Source)
 NS_DECLARE_NS_NEW_HTML_ELEMENT(Span)
 NS_DECLARE_NS_NEW_HTML_ELEMENT(Style)
diff --git a/dom/webidl/HTMLSlotElement.webidl b/dom/webidl/HTMLSlotElement.webidl
new file mode 100644
index 000000000..24dfcf350
--- /dev/null
+++ b/dom/webidl/HTMLSlotElement.webidl
@@ -0,0 +1,22 @@
+/* -*- Mode: IDL; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
+/* 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/.
+ *
+ * The origin of this IDL file is
+ * https://html.spec.whatwg.org/multipage/forms.html#the-dialog-element
+ *
+ * © Copyright 2004-2011 Apple Computer, Inc., Mozilla Foundation, and
+ * Opera Software ASA. You are granted a license to use, reproduce
+ * and create derivative works of this document.
+ */
+
+[Func="nsDocument::IsWebComponentsEnabled", Exposed=Window, HTMLConstructor]
+interface HTMLSlotElement : HTMLElement {
+  [CEReactions, SetterThrows] attribute DOMString name;
+  sequence<Node> assignedNodes(optional AssignedNodesOptions options);
+};
+
+dictionary AssignedNodesOptions {
+  boolean flatten = false;
+};
\ No newline at end of file
diff --git a/dom/webidl/moz.build b/dom/webidl/moz.build
index dba8e2818..ae97bbb30 100644
--- a/dom/webidl/moz.build
+++ b/dom/webidl/moz.build
@@ -226,6 +226,7 @@ WEBIDL_FILES = [
     'HTMLQuoteElement.webidl',
     'HTMLScriptElement.webidl',
     'HTMLSelectElement.webidl',
+    'HTMLSlotElement.webidl',
     'HTMLSourceElement.webidl',
     'HTMLSpanElement.webidl',
     'HTMLStyleElement.webidl',
diff --git a/editor/libeditor/HTMLEditUtils.cpp b/editor/libeditor/HTMLEditUtils.cpp
index 7933637fe..89abbe49c 100644
--- a/editor/libeditor/HTMLEditUtils.cpp
+++ b/editor/libeditor/HTMLEditUtils.cpp
@@ -603,9 +603,11 @@ static const ElementInfo kElements[eHTMLTag_userdefined] = {
   ELEM(a, true, false, GROUP_SPECIAL, GROUP_INLINE_ELEMENT),
   ELEM(abbr, true, true, GROUP_PHRASE, GROUP_INLINE_ELEMENT),
   ELEM(acronym, true, true, GROUP_PHRASE, GROUP_INLINE_ELEMENT),
-  ELEM(address, true, true, GROUP_BLOCK,
-       GROUP_INLINE_ELEMENT | GROUP_P),
-  ELEM(applet, true, true, GROUP_SPECIAL | GROUP_BLOCK,
+  ELEM(address, true, true, GROUP_BLOCK, GROUP_INLINE_ELEMENT | GROUP_P),
+  ELEM(applet,
+       true,
+       true,
+       GROUP_SPECIAL | GROUP_BLOCK,
        GROUP_FLOW_ELEMENT | GROUP_OBJECT_CONTENT),
   ELEM(area, false, false, GROUP_MAP_CONTENT, GROUP_NONE),
   ELEM(article, true, true, GROUP_BLOCK, GROUP_FLOW_ELEMENT),
@@ -620,19 +622,24 @@ static const ElementInfo kElements[eHTMLTag_userdefined] = {
   ELEM(blockquote, true, true, GROUP_BLOCK, GROUP_FLOW_ELEMENT),
   ELEM(body, true, true, GROUP_TOPLEVEL, GROUP_FLOW_ELEMENT),
   ELEM(br, false, false, GROUP_SPECIAL, GROUP_NONE),
-  ELEM(button, true, true, GROUP_FORMCONTROL | GROUP_BLOCK,
-       GROUP_FLOW_ELEMENT),
+  ELEM(button, true, true, GROUP_FORMCONTROL | GROUP_BLOCK, GROUP_FLOW_ELEMENT),
   ELEM(canvas, false, false, GROUP_NONE, GROUP_NONE),
   ELEM(caption, true, true, GROUP_NONE, GROUP_INLINE_ELEMENT),
   ELEM(center, true, true, GROUP_BLOCK, GROUP_FLOW_ELEMENT),
   ELEM(cite, true, true, GROUP_PHRASE, GROUP_INLINE_ELEMENT),
   ELEM(code, true, true, GROUP_PHRASE, GROUP_INLINE_ELEMENT),
-  ELEM(col, false, false, GROUP_TABLE_CONTENT | GROUP_COLGROUP_CONTENT,
+  ELEM(col,
+       false,
+       false,
+       GROUP_TABLE_CONTENT | GROUP_COLGROUP_CONTENT,
        GROUP_NONE),
   ELEM(colgroup, true, false, GROUP_NONE, GROUP_COLGROUP_CONTENT),
   ELEM(content, true, false, GROUP_NONE, GROUP_INLINE_ELEMENT),
   ELEM(data, true, false, GROUP_PHRASE, GROUP_INLINE_ELEMENT),
-  ELEM(datalist, true, false, GROUP_PHRASE,
+  ELEM(datalist,
+       true,
+       false,
+       GROUP_PHRASE,
        GROUP_OPTIONS | GROUP_INLINE_ELEMENT),
   ELEM(dd, true, false, GROUP_DL_CONTENT, GROUP_FLOW_ELEMENT),
   ELEM(del, true, true, GROUP_PHRASE | GROUP_BLOCK, GROUP_FLOW_ELEMENT),
@@ -647,33 +654,25 @@ static const ElementInfo kElements[eHTMLTag_userdefined] = {
   ELEM(embed, false, false, GROUP_NONE, GROUP_NONE),
   ELEM(fieldset, true, true, GROUP_BLOCK, GROUP_FLOW_ELEMENT),
   ELEM(figcaption, true, false, GROUP_FIGCAPTION, GROUP_FLOW_ELEMENT),
-  ELEM(figure, true, true, GROUP_BLOCK,
-       GROUP_FLOW_ELEMENT | GROUP_FIGCAPTION),
+  ELEM(figure, true, true, GROUP_BLOCK, GROUP_FLOW_ELEMENT | GROUP_FIGCAPTION),
   ELEM(font, true, true, GROUP_SPECIAL, GROUP_INLINE_ELEMENT),
   ELEM(footer, true, true, GROUP_BLOCK, GROUP_FLOW_ELEMENT),
   ELEM(form, true, true, GROUP_BLOCK, GROUP_FLOW_ELEMENT),
   ELEM(frame, false, false, GROUP_FRAME, GROUP_NONE),
   ELEM(frameset, true, true, GROUP_FRAME, GROUP_FRAME),
-  ELEM(h1, true, false, GROUP_BLOCK | GROUP_HEADING,
-       GROUP_INLINE_ELEMENT),
-  ELEM(h2, true, false, GROUP_BLOCK | GROUP_HEADING,
-       GROUP_INLINE_ELEMENT),
-  ELEM(h3, true, false, GROUP_BLOCK | GROUP_HEADING,
-       GROUP_INLINE_ELEMENT),
-  ELEM(h4, true, false, GROUP_BLOCK | GROUP_HEADING,
-       GROUP_INLINE_ELEMENT),
-  ELEM(h5, true, false, GROUP_BLOCK | GROUP_HEADING,
-       GROUP_INLINE_ELEMENT),
-  ELEM(h6, true, false, GROUP_BLOCK | GROUP_HEADING,
-       GROUP_INLINE_ELEMENT),
+  ELEM(h1, true, false, GROUP_BLOCK | GROUP_HEADING, GROUP_INLINE_ELEMENT),
+  ELEM(h2, true, false, GROUP_BLOCK | GROUP_HEADING, GROUP_INLINE_ELEMENT),
+  ELEM(h3, true, false, GROUP_BLOCK | GROUP_HEADING, GROUP_INLINE_ELEMENT),
+  ELEM(h4, true, false, GROUP_BLOCK | GROUP_HEADING, GROUP_INLINE_ELEMENT),
+  ELEM(h5, true, false, GROUP_BLOCK | GROUP_HEADING, GROUP_INLINE_ELEMENT),
+  ELEM(h6, true, false, GROUP_BLOCK | GROUP_HEADING, GROUP_INLINE_ELEMENT),
   ELEM(head, true, false, GROUP_TOPLEVEL, GROUP_HEAD_CONTENT),
   ELEM(header, true, true, GROUP_BLOCK, GROUP_FLOW_ELEMENT),
   ELEM(hgroup, true, false, GROUP_BLOCK, GROUP_HEADING),
   ELEM(hr, false, false, GROUP_BLOCK, GROUP_NONE),
   ELEM(html, true, false, GROUP_TOPLEVEL, GROUP_TOPLEVEL),
   ELEM(i, true, true, GROUP_FONTSTYLE, GROUP_INLINE_ELEMENT),
-  ELEM(iframe, true, true, GROUP_SPECIAL | GROUP_BLOCK,
-       GROUP_FLOW_ELEMENT),
+  ELEM(iframe, true, true, GROUP_SPECIAL | GROUP_BLOCK, GROUP_FLOW_ELEMENT),
   ELEM(image, false, false, GROUP_NONE, GROUP_NONE),
   ELEM(img, false, false, GROUP_SPECIAL | GROUP_PICTURE_CONTENT, GROUP_NONE),
   ELEM(input, false, false, GROUP_FORMCONTROL, GROUP_NONE),
@@ -699,15 +698,15 @@ static const ElementInfo kElements[eHTMLTag_userdefined] = {
   ELEM(noembed, false, false, GROUP_NONE, GROUP_NONE),
   ELEM(noframes, true, true, GROUP_BLOCK, GROUP_FLOW_ELEMENT),
   ELEM(noscript, true, true, GROUP_BLOCK, GROUP_FLOW_ELEMENT),
-  ELEM(object, true, true, GROUP_SPECIAL | GROUP_BLOCK,
+  ELEM(object,
+       true,
+       true,
+       GROUP_SPECIAL | GROUP_BLOCK,
        GROUP_FLOW_ELEMENT | GROUP_OBJECT_CONTENT),
   // XXX Can contain self and ul because editor does sublists illegally.
-  ELEM(ol, true, true, GROUP_BLOCK | GROUP_OL_UL,
-       GROUP_LI | GROUP_OL_UL),
-  ELEM(optgroup, true, false, GROUP_SELECT_CONTENT,
-       GROUP_OPTIONS),
-  ELEM(option, true, false,
-       GROUP_SELECT_CONTENT | GROUP_OPTIONS, GROUP_LEAF),
+  ELEM(ol, true, true, GROUP_BLOCK | GROUP_OL_UL, GROUP_LI | GROUP_OL_UL),
+  ELEM(optgroup, true, false, GROUP_SELECT_CONTENT, GROUP_OPTIONS),
+  ELEM(option, true, false, GROUP_SELECT_CONTENT | GROUP_OPTIONS, GROUP_LEAF),
   ELEM(output, true, true, GROUP_SPECIAL, GROUP_INLINE_ELEMENT),
   ELEM(p, true, false, GROUP_BLOCK | GROUP_P, GROUP_INLINE_ELEMENT),
   ELEM(param, false, false, GROUP_OBJECT_CONTENT, GROUP_NONE),
@@ -723,11 +722,11 @@ static const ElementInfo kElements[eHTMLTag_userdefined] = {
   ELEM(ruby, true, true, GROUP_PHRASE, GROUP_INLINE_ELEMENT),
   ELEM(s, true, true, GROUP_FONTSTYLE, GROUP_INLINE_ELEMENT),
   ELEM(samp, true, true, GROUP_PHRASE, GROUP_INLINE_ELEMENT),
-  ELEM(script, true, false, GROUP_HEAD_CONTENT | GROUP_SPECIAL,
-       GROUP_LEAF),
+  ELEM(script, true, false, GROUP_HEAD_CONTENT | GROUP_SPECIAL, GROUP_LEAF),
   ELEM(section, true, true, GROUP_BLOCK, GROUP_FLOW_ELEMENT),
   ELEM(select, true, false, GROUP_FORMCONTROL, GROUP_SELECT_CONTENT),
   ELEM(small, true, true, GROUP_FONTSTYLE, GROUP_INLINE_ELEMENT),
+  ELEM(slot, true, false, GROUP_NONE, GROUP_FLOW_ELEMENT),
   ELEM(source, false, false, GROUP_PICTURE_CONTENT, GROUP_NONE),
   ELEM(span, true, true, GROUP_SPECIAL, GROUP_INLINE_ELEMENT),
   ELEM(strike, true, true, GROUP_FONTSTYLE, GROUP_INLINE_ELEMENT),
@@ -751,8 +750,7 @@ static const ElementInfo kElements[eHTMLTag_userdefined] = {
   ELEM(tt, true, true, GROUP_FONTSTYLE, GROUP_INLINE_ELEMENT),
   ELEM(u, true, true, GROUP_FONTSTYLE, GROUP_INLINE_ELEMENT),
   // XXX Can contain self and ol because editor does sublists illegally.
-  ELEM(ul, true, true, GROUP_BLOCK | GROUP_OL_UL,
-       GROUP_LI | GROUP_OL_UL),
+  ELEM(ul, true, true, GROUP_BLOCK | GROUP_OL_UL, GROUP_LI | GROUP_OL_UL),
   ELEM(var, true, true, GROUP_PHRASE, GROUP_INLINE_ELEMENT),
   ELEM(video, false, false, GROUP_NONE, GROUP_NONE),
   ELEM(wbr, false, false, GROUP_NONE, GROUP_NONE),
diff --git a/parser/html/java/htmlparser/src/nu/validator/htmlparser/impl/ElementName.java b/parser/html/java/htmlparser/src/nu/validator/htmlparser/impl/ElementName.java
index b8e1b944c..5ab5a4ff8 100644
--- a/parser/html/java/htmlparser/src/nu/validator/htmlparser/impl/ElementName.java
+++ b/parser/html/java/htmlparser/src/nu/validator/htmlparser/impl/ElementName.java
@@ -2175,6 +2175,10 @@ public final class ElementName
     // CPPONLY: NS_NewHTMLUnknownElement,
     // CPPONLY: NS_NewSVGUnknownElement, 
     TreeBuilder.OTHER);
+    public static final ElementName SLOT = new ElementName("slot", "slot", 
+    // CPPONLY: NS_NewHTMLSlotElement,
+    // CPPONLY: NS_NewSVGUnknownElement, 
+    TreeBuilder.OTHER);
     public static final ElementName SCRIPT = new ElementName("script", "script", 
     // CPPONLY: NS_NewHTMLScriptElement,
     // CPPONLY: NS_NewSVGScriptElement, 
@@ -2270,18 +2274,18 @@ public final class ElementName
     private final static @NoLength ElementName[] ELEMENT_NAMES = {
     VKERN,
     LOGBASE,
-    FOREIGNOBJECT,
+    FIELDSET,
     DATA,
     LI,
-    CANVAS,
-    TT,
+    COMPLEXES,
+    QUOTIENT,
     PRE,
     ARTICLE,
     DIALOG,
     ARCTAN,
     LISTENER,
-    REALS,
-    MOMENT,
+    RATIONALS,
+    MROOT,
     MROW,
     GEQ,
     G,
@@ -2292,11 +2296,11 @@ public final class ElementName
     INTERVAL,
     MN,
     BR,
-    NOTANUMBER,
-    MPRESCRIPTS,
-    CARTESIANPRODUCT,
-    LT,
-    NEST,
+    POWER,
+    MMULTISCRIPTS,
+    CONTENT,
+    INTERSECT,
+    RT,
     SCRIPT,
     APPLY,
     COS,
@@ -2317,17 +2321,17 @@ public final class ElementName
     OPTION,
     MALIGNGROUP,
     FECOMPONENTTRANSFER,
-    MUNDEROVER,
-    SELECTOR,
-    EXISTS,
-    NATURALNUMBERS,
-    DT,
-    DATALIST,
-    FESPOTLIGHT,
-    LIMIT,
-    MTEXT,
-    OUTPUT,
-    ROOT,
+    MERROR,
+    VECTOR,
+    IMPLIES,
+    PRIMES,
+    APPLET,
+    EMPTYSET,
+    FEPOINTLIGHT,
+    LOWLIMIT,
+    NOTSUBSET,
+    PRODUCT,
+    SELECT,
     VECTORPRODUCT,
     FECOLORMATRIX,
     INFINITY,
@@ -2367,28 +2371,28 @@ public final class ElementName
     OPTGROUP,
     CENTER,
     FEGAUSSIANBLUR,
-    METER,
-    MLABELEDTR,
-    TR,
-    ARCCOS,
-    DEFS,
-    INTEGERS,
-    MINUS,
-    PROGRESS,
-    SEMANTICS,
-    ARCCOT,
-    GT,
-    EQUIVALENT,
-    FRAMESET,
-    FEDISTANTLIGHT,
-    IDENT,
-    LINEARGRADIENT,
-    MSQRT,
-    NOTPRSUBSET,
-    OBJECT,
-    PRSUBSET,
-    RECT,
-    SCALARPRODUCT,
+    MOVER,
+    NOBR,
+    SOLIDCOLOR,
+    ADDRESS,
+    DETAILS,
+    MS,
+    NOFRAMES,
+    PLUS,
+    TIMES,
+    BASEFONT,
+    DETERMINANT,
+    FONT_FACE_FORMAT,
+    FEOFFSET,
+    FONT,
+    INPUT,
+    LIST,
+    MOMENTABOUT,
+    NOSCRIPT,
+    OUTERPRODUCT,
+    PLAINTEXT,
+    RADIALGRADIENT,
+    SUBSET,
     TEXT,
     SDEV,
     VIEW,
@@ -2468,49 +2472,49 @@ public final class ElementName
     FOOTER,
     HANDLER,
     MARKER,
-    MOVER,
-    MERROR,
-    NOBR,
-    POWER,
-    SOLIDCOLOR,
-    VECTOR,
-    ADDRESS,
-    COMPLEXES,
-    DETAILS,
-    IMPLIES,
-    MS,
-    MMULTISCRIPTS,
-    NOFRAMES,
-    PRIMES,
-    PLUS,
-    RATIONALS,
-    TIMES,
-    APPLET,
-    BASEFONT,
-    CONTENT,
-    DETERMINANT,
-    EMPTYSET,
-    FONT_FACE_FORMAT,
-    FIELDSET,
-    FEOFFSET,
-    FEPOINTLIGHT,
-    FONT,
-    INTERSECT,
-    INPUT,
-    LOWLIMIT,
-    LIST,
-    MROOT,
-    MOMENTABOUT,
-    NOTSUBSET,
-    NOSCRIPT,
-    RT,
-    OUTERPRODUCT,
-    PRODUCT,
-    PLAINTEXT,
-    QUOTIENT,
-    RADIALGRADIENT,
-    SELECT,
-    SUBSET,
+    MUNDEROVER,
+    MLABELEDTR,
+    NOTANUMBER,
+    TR,
+    SELECTOR,
+    ARCCOS,
+    CANVAS,
+    DEFS,
+    EXISTS,
+    INTEGERS,
+    MPRESCRIPTS,
+    MINUS,
+    NATURALNUMBERS,
+    PROGRESS,
+    REALS,
+    SEMANTICS,
+    DT,
+    ARCCOT,
+    CARTESIANPRODUCT,
+    GT,
+    DATALIST,
+    EQUIVALENT,
+    FOREIGNOBJECT,
+    FRAMESET,
+    FESPOTLIGHT,
+    FEDISTANTLIGHT,
+    LT,
+    IDENT,
+    LIMIT,
+    LINEARGRADIENT,
+    MOMENT,
+    MSQRT,
+    MTEXT,
+    NOTPRSUBSET,
+    NEST,
+    OBJECT,
+    OUTPUT,
+    PRSUBSET,
+    TT,
+    RECT,
+    ROOT,
+    SCALARPRODUCT,
+    SLOT,
     TFOOT,
     UPLIMIT,
     MENU,
@@ -2668,22 +2672,23 @@ public final class ElementName
     HEADER,
     OR,
     MUNDER,
+    METER,
     };
     private final static int[] ELEMENT_HASHES = {
     1909280949,
     1753057319,
-    2001309869,
+    2001349704,
     1681770564,
     1818230786,
-    1982935782,
-    2006974466,
+    1983002201,
+    2007257240,
     58773795,
     1747176599,
     1782357526,
     1897999926,
     1970938456,
-    1990969429,
-    2005160150,
+    1990969577,
+    2005181733,
     2055514836,
     54061139,
     62390273,
@@ -2694,11 +2699,11 @@ public final class ElementName
     1868641064,
     1902641154,
     1963982850,
-    1971981018,
-    1988486811,
-    1999745104,
-    2002780162,
-    2005766372,
+    1973040373,
+    1988486813,
+    1999917383,
+    2002882873,
+    2005925890,
     2008340774,
     2082727685,
     51965171,
@@ -2719,17 +2724,17 @@ public final class ElementName
     1905563974,
     1938171179,
     1967788867,
-    1971467002,
-    1974775352,
-    1984294038,
-    1988972590,
-    1998585858,
-    2000525512,
-    2001392795,
-    2004557973,
-    2005324101,
-    2006329158,
-    2007803172,
+    1971628838,
+    1976348214,
+    1986140359,
+    1989812374,
+    1998724870,
+    2000825752,
+    2001392796,
+    2004557976,
+    2005543977,
+    2006560839,
+    2008125638,
     2009706573,
     2068523853,
     2087049448,
@@ -2769,28 +2774,28 @@ public final class ElementName
     1939219752,
     1966223078,
     1968053806,
-    1971465813,
-    1971703386,
-    1973420034,
-    1982106678,
-    1983533124,
-    1986351224,
-    1988502165,
-    1990037800,
-    1991350601,
-    1998883894,
-    2000158722,
-    2000965834,
-    2001349720,
-    2001392798,
-    2003062853,
-    2004635806,
-    2005231925,
-    2005543979,
-    2006028454,
-    2006592552,
-    2007601444,
-    2008133709,
+    1971466997,
+    1971938532,
+    1974771450,
+    1982173479,
+    1983633431,
+    1986527234,
+    1988763672,
+    1990074116,
+    1991909525,
+    1999397992,
+    2000439531,
+    2001281328,
+    2001349736,
+    2001495140,
+    2003183333,
+    2004719812,
+    2005279787,
+    2005719336,
+    2006036556,
+    2006896969,
+    2007781534,
+    2008165414,
     2008994116,
     2041712436,
     2060065124,
@@ -2870,49 +2875,49 @@ public final class ElementName
     1967795958,
     1968840263,
     1971461414,
-    1971466997,
-    1971628838,
-    1971938532,
-    1973040373,
-    1974771450,
-    1976348214,
-    1982173479,
-    1983002201,
-    1983633431,
-    1986140359,
-    1986527234,
-    1988486813,
-    1988763672,
-    1989812374,
-    1990074116,
-    1990969577,
-    1991909525,
-    1998724870,
-    1999397992,
-    1999917383,
-    2000439531,
-    2000825752,
-    2001281328,
-    2001349704,
-    2001349736,
-    2001392796,
-    2001495140,
-    2002882873,
-    2003183333,
-    2004557976,
-    2004719812,
-    2005181733,
-    2005279787,
-    2005543977,
-    2005719336,
-    2005925890,
-    2006036556,
-    2006560839,
-    2006896969,
-    2007257240,
-    2007781534,
-    2008125638,
-    2008165414,
+    1971467002,
+    1971703386,
+    1971981018,
+    1973420034,
+    1974775352,
+    1982106678,
+    1982935782,
+    1983533124,
+    1984294038,
+    1986351224,
+    1988486811,
+    1988502165,
+    1988972590,
+    1990037800,
+    1990969429,
+    1991350601,
+    1998585858,
+    1998883894,
+    1999745104,
+    2000158722,
+    2000525512,
+    2000965834,
+    2001309869,
+    2001349720,
+    2001392795,
+    2001392798,
+    2002780162,
+    2003062853,
+    2004557973,
+    2004635806,
+    2005160150,
+    2005231925,
+    2005324101,
+    2005543979,
+    2005766372,
+    2006028454,
+    2006329158,
+    2006592552,
+    2006974466,
+    2007601444,
+    2007803172,
+    2008133709,
+    2008325940,
     2008851557,
     2009276567,
     2021937364,
@@ -3070,5 +3075,6 @@ public final class ElementName
     1968836118,
     1970798594,
     1971457766,
+    1971465813,
     };
 }
diff --git a/parser/html/nsHtml5AtomList.h b/parser/html/nsHtml5AtomList.h
index 38fe05b0f..0728f439b 100644
--- a/parser/html/nsHtml5AtomList.h
+++ b/parser/html/nsHtml5AtomList.h
@@ -1049,6 +1049,7 @@ HTML5_ATOM(root, "root")
 HTML5_ATOM(select, "select")
 HTML5_ATOM(scalarproduct, "scalarproduct")
 HTML5_ATOM(subset, "subset")
+HTML5_ATOM(slot, "slot")
 HTML5_ATOM(script, "script")
 HTML5_ATOM(tfoot, "tfoot")
 HTML5_ATOM(uplimit, "uplimit")
diff --git a/parser/html/nsHtml5ElementName.cpp b/parser/html/nsHtml5ElementName.cpp
index 7b8d1fb20..788c9e36c 100644
--- a/parser/html/nsHtml5ElementName.cpp
+++ b/parser/html/nsHtml5ElementName.cpp
@@ -463,6 +463,7 @@ nsHtml5ElementName* nsHtml5ElementName::ELT_ROOT = nullptr;
 nsHtml5ElementName* nsHtml5ElementName::ELT_SELECT = nullptr;
 nsHtml5ElementName* nsHtml5ElementName::ELT_SCALARPRODUCT = nullptr;
 nsHtml5ElementName* nsHtml5ElementName::ELT_SUBSET = nullptr;
+nsHtml5ElementName* nsHtml5ElementName::ELT_SLOT = nullptr;
 nsHtml5ElementName* nsHtml5ElementName::ELT_SCRIPT = nullptr;
 nsHtml5ElementName* nsHtml5ElementName::ELT_TFOOT = nullptr;
 nsHtml5ElementName* nsHtml5ElementName::ELT_TEXT = nullptr;
@@ -487,7 +488,7 @@ nsHtml5ElementName* nsHtml5ElementName::ELT_RUBY = nullptr;
 nsHtml5ElementName* nsHtml5ElementName::ELT_SUMMARY = nullptr;
 nsHtml5ElementName* nsHtml5ElementName::ELT_TBODY = nullptr;
 nsHtml5ElementName** nsHtml5ElementName::ELEMENT_NAMES = 0;
-static int32_t const ELEMENT_HASHES_DATA[] = { 1909280949, 1753057319, 2001309869, 1681770564, 1818230786, 1982935782, 2006974466, 58773795, 1747176599, 1782357526, 1897999926, 1970938456, 1990969429, 2005160150, 2055514836, 54061139, 62390273, 1730150402, 1749395095, 1756625221, 1798693940, 1868641064, 1902641154, 1963982850, 1971981018, 1988486811, 1999745104, 2002780162, 2005766372, 2008340774, 2082727685, 51965171, 57200451, 60350803, 69730305, 1703292116, 1733890180, 1748355193, 1749813541, 1754634617, 1763839627, 1797540167, 1805647874, 1857622310, 1881498736, 1899272519, 1905563974, 1938171179, 1967788867, 1971467002, 1974775352, 1984294038, 1988972590, 1998585858, 2000525512, 2001392795, 2004557973, 2005324101, 2006329158, 2007803172, 2009706573, 2068523853, 2087049448, 51434643, 52488851, 56151587, 57210387, 59826259, 60354131, 63438849, 926941186, 1686489160, 1715300574, 1732381397, 1737099991, 1748100148, 1748642422, 1749715159, 1751288021, 1753467414, 1755158905, 1757259017, 1771722827, 1786534215, 1797645367, 1803929812, 1807501636, 1853642948, 1865773108, 1873350948, 1887579800, 1898223949, 1900544002, 1904285766, 1907435316, 1925844629, 1939219752, 1966223078, 1968053806, 1971465813, 1971703386, 1973420034, 1982106678, 1983533124, 1986351224, 1988502165, 1990037800, 1991350601, 1998883894, 2000158722, 2000965834, 2001349720, 2001392798, 2003062853, 2004635806, 2005231925, 2005543979, 2006028454, 2006592552, 2007601444, 2008133709, 2008994116, 2041712436, 2060065124, 2070023911, 2085266636, 2092255447, 50910499, 51957043, 52485715, 53012355, 55110883, 56680499, 57206291, 57732851, 59768833, 60345427, 60352083, 61395251, 62973651, 67633153, 893386754, 960495618, 1682547543, 1689922072, 1713515574, 1716349149, 1731545140, 1733076167, 1736576231, 1740181637, 1747814436, 1748228205, 1748607578, 1748879564, 1749656156, 1749801286, 1749917205, 1751493207, 1753343188, 1753588936, 1755076808, 1756474198, 1757146773, 1757293380, 1766632184, 1773808452, 1783388497, 1797361975, 1797585096, 1798677556, 1803876550, 1805233752, 1806806678, 1813512194, 1818755074, 1854228698, 1864368130, 1867237670, 1870268949, 1874102998, 1881669634, 1889085973, 1898223945, 1898971138, 1899694294, 1901940917, 1903761465, 1904515399, 1906135367, 1907959605, 1919418370, 1934172497, 1938173140, 1941221172, 1965334268, 1967128578, 1967795958, 1968840263, 1971461414, 1971466997, 1971628838, 1971938532, 1973040373, 1974771450, 1976348214, 1982173479, 1983002201, 1983633431, 1986140359, 1986527234, 1988486813, 1988763672, 1989812374, 1990074116, 1990969577, 1991909525, 1998724870, 1999397992, 1999917383, 2000439531, 2000825752, 2001281328, 2001349704, 2001349736, 2001392796, 2001495140, 2002882873, 2003183333, 2004557976, 2004719812, 2005181733, 2005279787, 2005543977, 2005719336, 2005925890, 2006036556, 2006560839, 2006896969, 2007257240, 2007781534, 2008125638, 2008165414, 2008851557, 2009276567, 2021937364, 2051837468, 2055515017, 2066000646, 2068523856, 2072193862, 2083120164, 2087012585, 2091479332, 2092557349, 50908899, 50916387, 51438659, 51961587, 51965683, 52486755, 52490899, 54054451, 55104723, 55111395, 56677619, 56682579, 57205395, 57207619, 57731155, 57733651, 59244545, 59821379, 60345171, 60347747, 60351123, 60352339, 60875283, 61925907, 62450211, 62974707, 67108865, 68681729, 876609538, 910163970, 943718402, 1679960596, 1682186266, 1685703382, 1686491348, 1699324759, 1703936002, 1713736758, 1715310660, 1719741029, 1730965751, 1732069431, 1733054663, 1733372532, 1736200310, 1736576583, 1738539010, 1747048757, 1747306711, 1747838298, 1748225318, 1748346119, 1748359220, 1748621670, 1748846791, 1749272732, 1749649513, 1749673195, 1749723735, 1749813486, 1749905526, 1749932347, 1751386406, 1752979652, 1753319686, 1753362711, 1753479494, 1754031332, 1754894485, 1755148615, 1756098852, 1756600614, 1757137429, 1757157700, 1757268168, 1758044696, 1765431364, 1766992520, 1773295687, 1781815495, 1783210839, 1783388498, 1790207270, 1797368887, 1797544247, 1797628983, 1798417460, 1798686984, 1800730821, 1803876557, 1803929861, 1805502724, 1806799156, 1806981428, 1807599880, 1817013469, 1818700314, 1820327938, 1854228692, 1854245076, 1857653029, 1865714391, 1867061545, 1868312196, 1870135298, 1873281026, 1874053333, 1881288348, 1881613047, 1884120164, 1887743720, 1897398274, 1898130486, 1898223946, 1898753862, 1899170008, 1899272521, 1899796819, 1900845386, 1902116866, 1903302038, 1904283860, 1904412884, 1904946933, 1906087319, 1907085604, 1907661127, 1908709605, 1914900309, 1925049415, 1932928296, 1935549734, 1938172967, 1938817026, 1941178676, 1948778498, 1965115924, 1965634084, 1966386470, 1967760215, 1967795910, 1967957189, 1968836118, 1970798594, 1971457766 };
+static int32_t const ELEMENT_HASHES_DATA[] = { 1909280949, 1753057319, 2001349704, 1681770564, 1818230786, 1983002201, 2007257240, 58773795, 1747176599, 1782357526, 1897999926, 1970938456, 1990969577, 2005181733, 2055514836, 54061139, 62390273, 1730150402, 1749395095, 1756625221, 1798693940, 1868641064, 1902641154, 1963982850, 1973040373, 1988486813, 1999917383, 2002882873, 2005925890, 2008340774, 2082727685, 51965171, 57200451, 60350803, 69730305, 1703292116, 1733890180, 1748355193, 1749813541, 1754634617, 1763839627, 1797540167, 1805647874, 1857622310, 1881498736, 1899272519, 1905563974, 1938171179, 1967788867, 1971628838, 1976348214, 1986140359, 1989812374, 1998724870, 2000825752, 2001392796, 2004557976, 2005543977, 2006560839, 2008125638, 2009706573, 2068523853, 2087049448, 51434643, 52488851, 56151587, 57210387, 59826259, 60354131, 63438849, 926941186, 1686489160, 1715300574, 1732381397, 1737099991, 1748100148, 1748642422, 1749715159, 1751288021, 1753467414, 1755158905, 1757259017, 1771722827, 1786534215, 1797645367, 1803929812, 1807501636, 1853642948, 1865773108, 1873350948, 1887579800, 1898223949, 1900544002, 1904285766, 1907435316, 1925844629, 1939219752, 1966223078, 1968053806, 1971466997, 1971938532, 1974771450, 1982173479, 1983633431, 1986527234, 1988763672, 1990074116, 1991909525, 1999397992, 2000439531, 2001281328, 2001349736, 2001495140, 2003183333, 2004719812, 2005279787, 2005719336, 2006036556, 2006896969, 2007781534, 2008165414, 2008994116, 2041712436, 2060065124, 2070023911, 2085266636, 2092255447, 50910499, 51957043, 52485715, 53012355, 55110883, 56680499, 57206291, 57732851, 59768833, 60345427, 60352083, 61395251, 62973651, 67633153, 893386754, 960495618, 1682547543, 1689922072, 1713515574, 1716349149, 1731545140, 1733076167, 1736576231, 1740181637, 1747814436, 1748228205, 1748607578, 1748879564, 1749656156, 1749801286, 1749917205, 1751493207, 1753343188, 1753588936, 1755076808, 1756474198, 1757146773, 1757293380, 1766632184, 1773808452, 1783388497, 1797361975, 1797585096, 1798677556, 1803876550, 1805233752, 1806806678, 1813512194, 1818755074, 1854228698, 1864368130, 1867237670, 1870268949, 1874102998, 1881669634, 1889085973, 1898223945, 1898971138, 1899694294, 1901940917, 1903761465, 1904515399, 1906135367, 1907959605, 1919418370, 1934172497, 1938173140, 1941221172, 1965334268, 1967128578, 1967795958, 1968840263, 1971461414, 1971467002, 1971703386, 1971981018, 1973420034, 1974775352, 1982106678, 1982935782, 1983533124, 1984294038, 1986351224, 1988486811, 1988502165, 1988972590, 1990037800, 1990969429, 1991350601, 1998585858, 1998883894, 1999745104, 2000158722, 2000525512, 2000965834, 2001309869, 2001349720, 2001392795, 2001392798, 2002780162, 2003062853, 2004557973, 2004635806, 2005160150, 2005231925, 2005324101, 2005543979, 2005766372, 2006028454, 2006329158, 2006592552, 2006974466, 2007601444, 2007803172, 2008133709, 2008325940, 2008851557, 2009276567, 2021937364, 2051837468, 2055515017, 2066000646, 2068523856, 2072193862, 2083120164, 2087012585, 2091479332, 2092557349, 50908899, 50916387, 51438659, 51961587, 51965683, 52486755, 52490899, 54054451, 55104723, 55111395, 56677619, 56682579, 57205395, 57207619, 57731155, 57733651, 59244545, 59821379, 60345171, 60347747, 60351123, 60352339, 60875283, 61925907, 62450211, 62974707, 67108865, 68681729, 876609538, 910163970, 943718402, 1679960596, 1682186266, 1685703382, 1686491348, 1699324759, 1703936002, 1713736758, 1715310660, 1719741029, 1730965751, 1732069431, 1733054663, 1733372532, 1736200310, 1736576583, 1738539010, 1747048757, 1747306711, 1747838298, 1748225318, 1748346119, 1748359220, 1748621670, 1748846791, 1749272732, 1749649513, 1749673195, 1749723735, 1749813486, 1749905526, 1749932347, 1751386406, 1752979652, 1753319686, 1753362711, 1753479494, 1754031332, 1754894485, 1755148615, 1756098852, 1756600614, 1757137429, 1757157700, 1757268168, 1758044696, 1765431364, 1766992520, 1773295687, 1781815495, 1783210839, 1783388498, 1790207270, 1797368887, 1797544247, 1797628983, 1798417460, 1798686984, 1800730821, 1803876557, 1803929861, 1805502724, 1806799156, 1806981428, 1807599880, 1817013469, 1818700314, 1820327938, 1854228692, 1854245076, 1857653029, 1865714391, 1867061545, 1868312196, 1870135298, 1873281026, 1874053333, 1881288348, 1881613047, 1884120164, 1887743720, 1897398274, 1898130486, 1898223946, 1898753862, 1899170008, 1899272521, 1899796819, 1900845386, 1902116866, 1903302038, 1904283860, 1904412884, 1904946933, 1906087319, 1907085604, 1907661127, 1908709605, 1914900309, 1925049415, 1932928296, 1935549734, 1938172967, 1938817026, 1941178676, 1948778498, 1965115924, 1965634084, 1966386470, 1967760215, 1967795910, 1967957189, 1968836118, 1970798594, 1971457766, 1971465813 };
 staticJArray<int32_t,int32_t> nsHtml5ElementName::ELEMENT_HASHES = { ELEMENT_HASHES_DATA, MOZ_ARRAY_LENGTH(ELEMENT_HASHES_DATA) };
 void
 nsHtml5ElementName::initializeStatics()
@@ -870,6 +871,7 @@ nsHtml5ElementName::initializeStatics()
   ELT_SELECT = new nsHtml5ElementName(nsHtml5Atoms::select, nsHtml5Atoms::select, NS_NewHTMLSelectElement, NS_NewSVGUnknownElement, nsHtml5TreeBuilder::SELECT | SPECIAL);
   ELT_SCALARPRODUCT = new nsHtml5ElementName(nsHtml5Atoms::scalarproduct, nsHtml5Atoms::scalarproduct, NS_NewHTMLUnknownElement, NS_NewSVGUnknownElement, nsHtml5TreeBuilder::OTHER);
   ELT_SUBSET = new nsHtml5ElementName(nsHtml5Atoms::subset, nsHtml5Atoms::subset, NS_NewHTMLUnknownElement, NS_NewSVGUnknownElement, nsHtml5TreeBuilder::OTHER);
+  ELT_SLOT = new nsHtml5ElementName(nsHtml5Atoms::slot, nsHtml5Atoms::slot, NS_NewHTMLSlotElement, NS_NewSVGUnknownElement, nsHtml5TreeBuilder::OTHER);
   ELT_SCRIPT = new nsHtml5ElementName(nsHtml5Atoms::script, nsHtml5Atoms::script, NS_NewHTMLScriptElement, NS_NewSVGScriptElement, nsHtml5TreeBuilder::SCRIPT | SPECIAL);
   ELT_TFOOT = new nsHtml5ElementName(nsHtml5Atoms::tfoot, nsHtml5Atoms::tfoot, NS_NewHTMLTableSectionElement, NS_NewSVGUnknownElement, nsHtml5TreeBuilder::TBODY_OR_THEAD_OR_TFOOT | SPECIAL | FOSTER_PARENTING | OPTIONAL_END_TAG);
   ELT_TEXT = new nsHtml5ElementName(nsHtml5Atoms::text, nsHtml5Atoms::text, NS_NewHTMLUnknownElement, NS_NewSVGTextElement, nsHtml5TreeBuilder::OTHER);
@@ -893,21 +895,21 @@ nsHtml5ElementName::initializeStatics()
   ELT_RUBY = new nsHtml5ElementName(nsHtml5Atoms::ruby, nsHtml5Atoms::ruby, NS_NewHTMLElement, NS_NewSVGUnknownElement, nsHtml5TreeBuilder::RUBY_OR_SPAN_OR_SUB_OR_SUP_OR_VAR);
   ELT_SUMMARY = new nsHtml5ElementName(nsHtml5Atoms::summary, nsHtml5Atoms::summary, NS_NewHTMLSummaryElement, NS_NewSVGUnknownElement, nsHtml5TreeBuilder::ADDRESS_OR_ARTICLE_OR_ASIDE_OR_DETAILS_OR_DIALOG_OR_DIR_OR_FIGCAPTION_OR_FIGURE_OR_FOOTER_OR_HEADER_OR_HGROUP_OR_MAIN_OR_NAV_OR_SECTION_OR_SUMMARY | SPECIAL);
   ELT_TBODY = new nsHtml5ElementName(nsHtml5Atoms::tbody, nsHtml5Atoms::tbody, NS_NewHTMLTableSectionElement, NS_NewSVGUnknownElement, nsHtml5TreeBuilder::TBODY_OR_THEAD_OR_TFOOT | SPECIAL | FOSTER_PARENTING | OPTIONAL_END_TAG);
-  ELEMENT_NAMES = new nsHtml5ElementName*[400];
+  ELEMENT_NAMES = new nsHtml5ElementName*[401];
   ELEMENT_NAMES[0] = ELT_VKERN;
   ELEMENT_NAMES[1] = ELT_LOGBASE;
-  ELEMENT_NAMES[2] = ELT_FOREIGNOBJECT;
+  ELEMENT_NAMES[2] = ELT_FIELDSET;
   ELEMENT_NAMES[3] = ELT_DATA;
   ELEMENT_NAMES[4] = ELT_LI;
-  ELEMENT_NAMES[5] = ELT_CANVAS;
-  ELEMENT_NAMES[6] = ELT_TT;
+  ELEMENT_NAMES[5] = ELT_COMPLEXES;
+  ELEMENT_NAMES[6] = ELT_QUOTIENT;
   ELEMENT_NAMES[7] = ELT_PRE;
   ELEMENT_NAMES[8] = ELT_ARTICLE;
   ELEMENT_NAMES[9] = ELT_DIALOG;
   ELEMENT_NAMES[10] = ELT_ARCTAN;
   ELEMENT_NAMES[11] = ELT_LISTENER;
-  ELEMENT_NAMES[12] = ELT_REALS;
-  ELEMENT_NAMES[13] = ELT_MOMENT;
+  ELEMENT_NAMES[12] = ELT_RATIONALS;
+  ELEMENT_NAMES[13] = ELT_MROOT;
   ELEMENT_NAMES[14] = ELT_MROW;
   ELEMENT_NAMES[15] = ELT_GEQ;
   ELEMENT_NAMES[16] = ELT_G;
@@ -918,11 +920,11 @@ nsHtml5ElementName::initializeStatics()
   ELEMENT_NAMES[21] = ELT_INTERVAL;
   ELEMENT_NAMES[22] = ELT_MN;
   ELEMENT_NAMES[23] = ELT_BR;
-  ELEMENT_NAMES[24] = ELT_NOTANUMBER;
-  ELEMENT_NAMES[25] = ELT_MPRESCRIPTS;
-  ELEMENT_NAMES[26] = ELT_CARTESIANPRODUCT;
-  ELEMENT_NAMES[27] = ELT_LT;
-  ELEMENT_NAMES[28] = ELT_NEST;
+  ELEMENT_NAMES[24] = ELT_POWER;
+  ELEMENT_NAMES[25] = ELT_MMULTISCRIPTS;
+  ELEMENT_NAMES[26] = ELT_CONTENT;
+  ELEMENT_NAMES[27] = ELT_INTERSECT;
+  ELEMENT_NAMES[28] = ELT_RT;
   ELEMENT_NAMES[29] = ELT_SCRIPT;
   ELEMENT_NAMES[30] = ELT_APPLY;
   ELEMENT_NAMES[31] = ELT_COS;
@@ -943,17 +945,17 @@ nsHtml5ElementName::initializeStatics()
   ELEMENT_NAMES[46] = ELT_OPTION;
   ELEMENT_NAMES[47] = ELT_MALIGNGROUP;
   ELEMENT_NAMES[48] = ELT_FECOMPONENTTRANSFER;
-  ELEMENT_NAMES[49] = ELT_MUNDEROVER;
-  ELEMENT_NAMES[50] = ELT_SELECTOR;
-  ELEMENT_NAMES[51] = ELT_EXISTS;
-  ELEMENT_NAMES[52] = ELT_NATURALNUMBERS;
-  ELEMENT_NAMES[53] = ELT_DT;
-  ELEMENT_NAMES[54] = ELT_DATALIST;
-  ELEMENT_NAMES[55] = ELT_FESPOTLIGHT;
-  ELEMENT_NAMES[56] = ELT_LIMIT;
-  ELEMENT_NAMES[57] = ELT_MTEXT;
-  ELEMENT_NAMES[58] = ELT_OUTPUT;
-  ELEMENT_NAMES[59] = ELT_ROOT;
+  ELEMENT_NAMES[49] = ELT_MERROR;
+  ELEMENT_NAMES[50] = ELT_VECTOR;
+  ELEMENT_NAMES[51] = ELT_IMPLIES;
+  ELEMENT_NAMES[52] = ELT_PRIMES;
+  ELEMENT_NAMES[53] = ELT_APPLET;
+  ELEMENT_NAMES[54] = ELT_EMPTYSET;
+  ELEMENT_NAMES[55] = ELT_FEPOINTLIGHT;
+  ELEMENT_NAMES[56] = ELT_LOWLIMIT;
+  ELEMENT_NAMES[57] = ELT_NOTSUBSET;
+  ELEMENT_NAMES[58] = ELT_PRODUCT;
+  ELEMENT_NAMES[59] = ELT_SELECT;
   ELEMENT_NAMES[60] = ELT_VECTORPRODUCT;
   ELEMENT_NAMES[61] = ELT_FECOLORMATRIX;
   ELEMENT_NAMES[62] = ELT_INFINITY;
@@ -993,28 +995,28 @@ nsHtml5ElementName::initializeStatics()
   ELEMENT_NAMES[96] = ELT_OPTGROUP;
   ELEMENT_NAMES[97] = ELT_CENTER;
   ELEMENT_NAMES[98] = ELT_FEGAUSSIANBLUR;
-  ELEMENT_NAMES[99] = ELT_METER;
-  ELEMENT_NAMES[100] = ELT_MLABELEDTR;
-  ELEMENT_NAMES[101] = ELT_TR;
-  ELEMENT_NAMES[102] = ELT_ARCCOS;
-  ELEMENT_NAMES[103] = ELT_DEFS;
-  ELEMENT_NAMES[104] = ELT_INTEGERS;
-  ELEMENT_NAMES[105] = ELT_MINUS;
-  ELEMENT_NAMES[106] = ELT_PROGRESS;
-  ELEMENT_NAMES[107] = ELT_SEMANTICS;
-  ELEMENT_NAMES[108] = ELT_ARCCOT;
-  ELEMENT_NAMES[109] = ELT_GT;
-  ELEMENT_NAMES[110] = ELT_EQUIVALENT;
-  ELEMENT_NAMES[111] = ELT_FRAMESET;
-  ELEMENT_NAMES[112] = ELT_FEDISTANTLIGHT;
-  ELEMENT_NAMES[113] = ELT_IDENT;
-  ELEMENT_NAMES[114] = ELT_LINEARGRADIENT;
-  ELEMENT_NAMES[115] = ELT_MSQRT;
-  ELEMENT_NAMES[116] = ELT_NOTPRSUBSET;
-  ELEMENT_NAMES[117] = ELT_OBJECT;
-  ELEMENT_NAMES[118] = ELT_PRSUBSET;
-  ELEMENT_NAMES[119] = ELT_RECT;
-  ELEMENT_NAMES[120] = ELT_SCALARPRODUCT;
+  ELEMENT_NAMES[99] = ELT_MOVER;
+  ELEMENT_NAMES[100] = ELT_NOBR;
+  ELEMENT_NAMES[101] = ELT_SOLIDCOLOR;
+  ELEMENT_NAMES[102] = ELT_ADDRESS;
+  ELEMENT_NAMES[103] = ELT_DETAILS;
+  ELEMENT_NAMES[104] = ELT_MS;
+  ELEMENT_NAMES[105] = ELT_NOFRAMES;
+  ELEMENT_NAMES[106] = ELT_PLUS;
+  ELEMENT_NAMES[107] = ELT_TIMES;
+  ELEMENT_NAMES[108] = ELT_BASEFONT;
+  ELEMENT_NAMES[109] = ELT_DETERMINANT;
+  ELEMENT_NAMES[110] = ELT_FONT_FACE_FORMAT;
+  ELEMENT_NAMES[111] = ELT_FEOFFSET;
+  ELEMENT_NAMES[112] = ELT_FONT;
+  ELEMENT_NAMES[113] = ELT_INPUT;
+  ELEMENT_NAMES[114] = ELT_LIST;
+  ELEMENT_NAMES[115] = ELT_MOMENTABOUT;
+  ELEMENT_NAMES[116] = ELT_NOSCRIPT;
+  ELEMENT_NAMES[117] = ELT_OUTERPRODUCT;
+  ELEMENT_NAMES[118] = ELT_PLAINTEXT;
+  ELEMENT_NAMES[119] = ELT_RADIALGRADIENT;
+  ELEMENT_NAMES[120] = ELT_SUBSET;
   ELEMENT_NAMES[121] = ELT_TEXT;
   ELEMENT_NAMES[122] = ELT_SDEV;
   ELEMENT_NAMES[123] = ELT_VIEW;
@@ -1094,49 +1096,49 @@ nsHtml5ElementName::initializeStatics()
   ELEMENT_NAMES[197] = ELT_FOOTER;
   ELEMENT_NAMES[198] = ELT_HANDLER;
   ELEMENT_NAMES[199] = ELT_MARKER;
-  ELEMENT_NAMES[200] = ELT_MOVER;
-  ELEMENT_NAMES[201] = ELT_MERROR;
-  ELEMENT_NAMES[202] = ELT_NOBR;
-  ELEMENT_NAMES[203] = ELT_POWER;
-  ELEMENT_NAMES[204] = ELT_SOLIDCOLOR;
-  ELEMENT_NAMES[205] = ELT_VECTOR;
-  ELEMENT_NAMES[206] = ELT_ADDRESS;
-  ELEMENT_NAMES[207] = ELT_COMPLEXES;
-  ELEMENT_NAMES[208] = ELT_DETAILS;
-  ELEMENT_NAMES[209] = ELT_IMPLIES;
-  ELEMENT_NAMES[210] = ELT_MS;
-  ELEMENT_NAMES[211] = ELT_MMULTISCRIPTS;
-  ELEMENT_NAMES[212] = ELT_NOFRAMES;
-  ELEMENT_NAMES[213] = ELT_PRIMES;
-  ELEMENT_NAMES[214] = ELT_PLUS;
-  ELEMENT_NAMES[215] = ELT_RATIONALS;
-  ELEMENT_NAMES[216] = ELT_TIMES;
-  ELEMENT_NAMES[217] = ELT_APPLET;
-  ELEMENT_NAMES[218] = ELT_BASEFONT;
-  ELEMENT_NAMES[219] = ELT_CONTENT;
-  ELEMENT_NAMES[220] = ELT_DETERMINANT;
-  ELEMENT_NAMES[221] = ELT_EMPTYSET;
-  ELEMENT_NAMES[222] = ELT_FONT_FACE_FORMAT;
-  ELEMENT_NAMES[223] = ELT_FIELDSET;
-  ELEMENT_NAMES[224] = ELT_FEOFFSET;
-  ELEMENT_NAMES[225] = ELT_FEPOINTLIGHT;
-  ELEMENT_NAMES[226] = ELT_FONT;
-  ELEMENT_NAMES[227] = ELT_INTERSECT;
-  ELEMENT_NAMES[228] = ELT_INPUT;
-  ELEMENT_NAMES[229] = ELT_LOWLIMIT;
-  ELEMENT_NAMES[230] = ELT_LIST;
-  ELEMENT_NAMES[231] = ELT_MROOT;
-  ELEMENT_NAMES[232] = ELT_MOMENTABOUT;
-  ELEMENT_NAMES[233] = ELT_NOTSUBSET;
-  ELEMENT_NAMES[234] = ELT_NOSCRIPT;
-  ELEMENT_NAMES[235] = ELT_RT;
-  ELEMENT_NAMES[236] = ELT_OUTERPRODUCT;
-  ELEMENT_NAMES[237] = ELT_PRODUCT;
-  ELEMENT_NAMES[238] = ELT_PLAINTEXT;
-  ELEMENT_NAMES[239] = ELT_QUOTIENT;
-  ELEMENT_NAMES[240] = ELT_RADIALGRADIENT;
-  ELEMENT_NAMES[241] = ELT_SELECT;
-  ELEMENT_NAMES[242] = ELT_SUBSET;
+  ELEMENT_NAMES[200] = ELT_MUNDEROVER;
+  ELEMENT_NAMES[201] = ELT_MLABELEDTR;
+  ELEMENT_NAMES[202] = ELT_NOTANUMBER;
+  ELEMENT_NAMES[203] = ELT_TR;
+  ELEMENT_NAMES[204] = ELT_SELECTOR;
+  ELEMENT_NAMES[205] = ELT_ARCCOS;
+  ELEMENT_NAMES[206] = ELT_CANVAS;
+  ELEMENT_NAMES[207] = ELT_DEFS;
+  ELEMENT_NAMES[208] = ELT_EXISTS;
+  ELEMENT_NAMES[209] = ELT_INTEGERS;
+  ELEMENT_NAMES[210] = ELT_MPRESCRIPTS;
+  ELEMENT_NAMES[211] = ELT_MINUS;
+  ELEMENT_NAMES[212] = ELT_NATURALNUMBERS;
+  ELEMENT_NAMES[213] = ELT_PROGRESS;
+  ELEMENT_NAMES[214] = ELT_REALS;
+  ELEMENT_NAMES[215] = ELT_SEMANTICS;
+  ELEMENT_NAMES[216] = ELT_DT;
+  ELEMENT_NAMES[217] = ELT_ARCCOT;
+  ELEMENT_NAMES[218] = ELT_CARTESIANPRODUCT;
+  ELEMENT_NAMES[219] = ELT_GT;
+  ELEMENT_NAMES[220] = ELT_DATALIST;
+  ELEMENT_NAMES[221] = ELT_EQUIVALENT;
+  ELEMENT_NAMES[222] = ELT_FOREIGNOBJECT;
+  ELEMENT_NAMES[223] = ELT_FRAMESET;
+  ELEMENT_NAMES[224] = ELT_FESPOTLIGHT;
+  ELEMENT_NAMES[225] = ELT_FEDISTANTLIGHT;
+  ELEMENT_NAMES[226] = ELT_LT;
+  ELEMENT_NAMES[227] = ELT_IDENT;
+  ELEMENT_NAMES[228] = ELT_LIMIT;
+  ELEMENT_NAMES[229] = ELT_LINEARGRADIENT;
+  ELEMENT_NAMES[230] = ELT_MOMENT;
+  ELEMENT_NAMES[231] = ELT_MSQRT;
+  ELEMENT_NAMES[232] = ELT_MTEXT;
+  ELEMENT_NAMES[233] = ELT_NOTPRSUBSET;
+  ELEMENT_NAMES[234] = ELT_NEST;
+  ELEMENT_NAMES[235] = ELT_OBJECT;
+  ELEMENT_NAMES[236] = ELT_OUTPUT;
+  ELEMENT_NAMES[237] = ELT_PRSUBSET;
+  ELEMENT_NAMES[238] = ELT_TT;
+  ELEMENT_NAMES[239] = ELT_RECT;
+  ELEMENT_NAMES[240] = ELT_ROOT;
+  ELEMENT_NAMES[241] = ELT_SCALARPRODUCT;
+  ELEMENT_NAMES[242] = ELT_SLOT;
   ELEMENT_NAMES[243] = ELT_TFOOT;
   ELEMENT_NAMES[244] = ELT_UPLIMIT;
   ELEMENT_NAMES[245] = ELT_MENU;
@@ -1294,6 +1296,7 @@ nsHtml5ElementName::initializeStatics()
   ELEMENT_NAMES[397] = ELT_HEADER;
   ELEMENT_NAMES[398] = ELT_OR;
   ELEMENT_NAMES[399] = ELT_MUNDER;
+  ELEMENT_NAMES[400] = ELT_METER;
 }
 
 void
@@ -1677,6 +1680,7 @@ nsHtml5ElementName::releaseStatics()
   delete ELT_SELECT;
   delete ELT_SCALARPRODUCT;
   delete ELT_SUBSET;
+  delete ELT_SLOT;
   delete ELT_SCRIPT;
   delete ELT_TFOOT;
   delete ELT_TEXT;
diff --git a/parser/html/nsHtml5ElementName.h b/parser/html/nsHtml5ElementName.h
index da259d4da..022c610f4 100644
--- a/parser/html/nsHtml5ElementName.h
+++ b/parser/html/nsHtml5ElementName.h
@@ -586,6 +586,7 @@ class nsHtml5ElementName
     static nsHtml5ElementName* ELT_SELECT;
     static nsHtml5ElementName* ELT_SCALARPRODUCT;
     static nsHtml5ElementName* ELT_SUBSET;
+    static nsHtml5ElementName* ELT_SLOT;
     static nsHtml5ElementName* ELT_SCRIPT;
     static nsHtml5ElementName* ELT_TFOOT;
     static nsHtml5ElementName* ELT_TEXT;
diff --git a/parser/htmlparser/nsElementTable.cpp b/parser/htmlparser/nsElementTable.cpp
index b7742e56f..48fe4aede 100644
--- a/parser/htmlparser/nsElementTable.cpp
+++ b/parser/htmlparser/nsElementTable.cpp
@@ -145,6 +145,7 @@ static const HTMLElement gHTMLElements[] = {
   ELEM(section,     true, true)
   ELEM(select,      ____, true)
   ELEM(small,       ____, true)
+  ELEM(slot,        ____, true)
   ELEM(source,      ____, ____)
   ELEM(span,        ____, true)
   ELEM(strike,      ____, true)
diff --git a/parser/htmlparser/nsHTMLTagList.h b/parser/htmlparser/nsHTMLTagList.h
index 80d737ffb..b3bd7b0b7 100644
--- a/parser/htmlparser/nsHTMLTagList.h
+++ b/parser/htmlparser/nsHTMLTagList.h
@@ -154,6 +154,7 @@ HTML_TAG(script, Script, Script)
 HTML_HTMLELEMENT_TAG(section)
 HTML_TAG(select, Select, Select)
 HTML_HTMLELEMENT_TAG(small)
+HTML_TAG(slot, Slot, Slot)
 HTML_TAG(source, Source, Source)
 HTML_TAG(span, Span, Span)
 HTML_HTMLELEMENT_TAG(strike)