10 files changed, 57 insertions, 47 deletions
diff --git a/dom/webidl/AnonymousContent.webidl b/dom/webidl/AnonymousContent.webidl
index 6755fe598..8be69cd26 100644
--- a/dom/webidl/AnonymousContent.webidl
+++ b/dom/webidl/AnonymousContent.webidl
@@ -77,4 +77,12 @@ interface AnonymousContent {
   [Throws]
   void setCutoutRectsForElement(DOMString elementId,
                                 sequence<DOMRect> rects);
+
+  /**
+   * Get the computed value of a property on an element inside this custom
+   * anonymous content.
+   */
+  [Throws]
+  DOMString? getComputedStylePropertyValue(DOMString elementId,
+                                           DOMString propertyName);
 };
diff --git a/dom/webidl/Document.webidl b/dom/webidl/Document.webidl
index b28903ae2..ba2ec17ea 100644
--- a/dom/webidl/Document.webidl
+++ b/dom/webidl/Document.webidl
@@ -17,6 +17,9 @@ enum VisibilityState { "hidden", "visible", "prerender" };
 /* https://dom.spec.whatwg.org/#dictdef-elementcreationoptions */
 dictionary ElementCreationOptions {
   DOMString is;
+
+  [ChromeOnly]
+  DOMString pseudo;
 };
 
 /* http://dom.spec.whatwg.org/#interface-document */
@@ -268,13 +271,6 @@ partial interface Document {
   attribute EventHandler onpointerlockerror;
 };
 
-//http://dvcs.w3.org/hg/webcomponents/raw-file/tip/spec/custom/index.html#dfn-document-register
-partial interface Document {
-    // this is deprecated from CustomElements v0
-    [Throws, Func="CustomElementRegistry::IsCustomElementEnabled"]
-    object registerElement(DOMString name, optional ElementRegistrationOptions options);
-};
-
 // https://w3c.github.io/page-visibility/#extensions-to-the-document-interface
 partial interface Document {
   [Pref="dom.visibilityAPI.enabled"]
diff --git a/dom/webidl/Element.webidl b/dom/webidl/Element.webidl
index a6b2bfdd5..d5cac7c64 100644
--- a/dom/webidl/Element.webidl
+++ b/dom/webidl/Element.webidl
@@ -228,14 +228,26 @@ partial interface Element {
   NodeList  querySelectorAll(DOMString selectors);
 };
 
-// http://w3c.github.io/webcomponents/spec/shadow/#extensions-to-element-interface
+// https://dom.spec.whatwg.org/#dictdef-shadowrootinit
+dictionary ShadowRootInit {
+  required ShadowRootMode mode;
+};
+
+// https://dom.spec.whatwg.org/#element
 partial interface Element {
-  [Throws,Func="nsDocument::IsWebComponentsEnabled"]
-  ShadowRoot createShadowRoot();
-  [Func="nsDocument::IsWebComponentsEnabled"]
-  NodeList getDestinationInsertionPoints();
-  [Func="nsDocument::IsWebComponentsEnabled"]
+  // Shadow DOM v1
+  [Throws, Func="nsDocument::IsWebComponentsEnabled"]
+  ShadowRoot attachShadow(ShadowRootInit shadowRootInitDict);
+  [BinaryName="shadowRootByMode", Func="nsDocument::IsWebComponentsEnabled"]
   readonly attribute ShadowRoot? shadowRoot;
+  [BinaryName="assignedSlotByMode", Func="nsDocument::IsWebComponentsEnabled"]
+  readonly attribute HTMLSlotElement? assignedSlot;
+  [CEReactions, Unscopable, SetterThrows, Func="nsDocument::IsWebComponentsEnabled"]
+           attribute DOMString slot;
+
+  // [deprecated] Shadow DOM v0
+  [Throws, Func="nsDocument::IsWebComponentsEnabled"]
+  ShadowRoot createShadowRoot();
 };
 
 Element implements ChildNode;
diff --git a/dom/webidl/Event.webidl b/dom/webidl/Event.webidl
index a5d7da7d4..8a8e71c43 100644
--- a/dom/webidl/Event.webidl
+++ b/dom/webidl/Event.webidl
@@ -22,6 +22,8 @@ interface Event {
   [Pure]
   readonly attribute EventTarget? currentTarget;
 
+  sequence<EventTarget> composedPath();
+
   const unsigned short NONE = 0;
   const unsigned short CAPTURING_PHASE = 1;
   const unsigned short AT_TARGET = 2;
diff --git a/dom/webidl/HTMLShadowElement.webidl b/dom/webidl/HTMLShadowElement.webidl
deleted file mode 100644
index f72cd06e1..000000000
--- a/dom/webidl/HTMLShadowElement.webidl
+++ /dev/null
@@ -1,19 +0,0 @@
-/* -*- 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://dvcs.w3.org/hg/webcomponents/raw-file/tip/spec/shadow/index.html
- *
- * © 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"]
-interface HTMLShadowElement : HTMLElement
-{
-  readonly attribute ShadowRoot? olderShadowRoot;
-};
-
diff --git a/dom/webidl/HTMLContentElement.webidl b/dom/webidl/HTMLSlotElement.webidl
index ea809f120..24dfcf350 100644
--- a/dom/webidl/HTMLContentElement.webidl
+++ b/dom/webidl/HTMLSlotElement.webidl
@@ -4,17 +4,19 @@
  * You can obtain one at http://mozilla.org/MPL/2.0/.
  *
  * The origin of this IDL file is
- * https://dvcs.w3.org/hg/webcomponents/raw-file/tip/spec/shadow/index.html
+ * 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"]
-interface HTMLContentElement : HTMLElement
-{
-  attribute DOMString select;
-  NodeList getDistributedNodes();
+[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/ShadowRoot.webidl b/dom/webidl/ShadowRoot.webidl
index 8dd069244..47e6cf5ec 100644
--- a/dom/webidl/ShadowRoot.webidl
+++ b/dom/webidl/ShadowRoot.webidl
@@ -10,17 +10,27 @@
  * liability, trademark and document use rules apply.
  */
 
+// https://dom.spec.whatwg.org/#enumdef-shadowrootmode
+enum ShadowRootMode {
+  "open",
+  "closed"
+};
+
+// https://dom.spec.whatwg.org/#shadowroot
 [Func="nsDocument::IsWebComponentsEnabled"]
 interface ShadowRoot : DocumentFragment
 {
+  // Shadow DOM v1
+  readonly attribute ShadowRootMode mode;
+  readonly attribute Element host;
+
+  // [deprecated] Shadow DOM v0
   Element? getElementById(DOMString elementId);
   HTMLCollection getElementsByTagName(DOMString localName);
   HTMLCollection getElementsByTagNameNS(DOMString? namespace, DOMString localName);
   HTMLCollection getElementsByClassName(DOMString classNames);
   [CEReactions, SetterThrows, TreatNullAs=EmptyString]
   attribute DOMString innerHTML;
-  readonly attribute Element host;
-  readonly attribute ShadowRoot? olderShadowRoot;
   attribute boolean applyAuthorStyles;
   readonly attribute StyleSheetList styleSheets;
 };
diff --git a/dom/webidl/Text.webidl b/dom/webidl/Text.webidl
index dcd25cec3..fb7b5d685 100644
--- a/dom/webidl/Text.webidl
+++ b/dom/webidl/Text.webidl
@@ -18,4 +18,9 @@ interface Text : CharacterData {
   readonly attribute DOMString wholeText;
 };
 
+partial interface Text {
+  [BinaryName="assignedSlotByMode", Func="nsTextNode::IsWebComponentsEnabled"]
+  readonly attribute HTMLSlotElement? assignedSlot;
+};
+
 Text implements GeometryUtils;
diff --git a/dom/webidl/WebComponents.webidl b/dom/webidl/WebComponents.webidl
index f9bb8214a..9c5e53131 100644
--- a/dom/webidl/WebComponents.webidl
+++ b/dom/webidl/WebComponents.webidl
@@ -25,8 +25,3 @@ dictionary LifecycleCallbacks {
   LifecycleAdoptedCallback? adoptedCallback;
   LifecycleAttributeChangedCallback? attributeChangedCallback;
 };
-
-dictionary ElementRegistrationOptions {
-  object? prototype = null;
-  DOMString? extends = null;
-};
diff --git a/dom/webidl/moz.build b/dom/webidl/moz.build
index 156da302d..d76a58e1f 100644
--- a/dom/webidl/moz.build
+++ b/dom/webidl/moz.build
@@ -177,7 +177,6 @@ WEBIDL_FILES = [
     'HTMLButtonElement.webidl',
     'HTMLCanvasElement.webidl',
     'HTMLCollection.webidl',
-    'HTMLContentElement.webidl',
     'HTMLDataElement.webidl',
     'HTMLDataListElement.webidl',
     'HTMLDetailsElement.webidl',
@@ -226,7 +225,7 @@ WEBIDL_FILES = [
     'HTMLQuoteElement.webidl',
     'HTMLScriptElement.webidl',
     'HTMLSelectElement.webidl',
-    'HTMLShadowElement.webidl',
+    'HTMLSlotElement.webidl',
     'HTMLSourceElement.webidl',
     'HTMLSpanElement.webidl',
     'HTMLStyleElement.webidl',