7 files changed, 147 insertions, 0 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',