Sync HTML element interfaces H-K with the spec

Source/core/html/HTMLIFrameElement.idl

 /*
  * Copyright (C) 2006, 2007, 2009, 2010 Apple Inc. All rights reserved.
  * Copyright (C) 2006 Samuel Weinig <sam.weinig@gmail.com>
  *
  * This library is free software; you can redistribute it and/or
  * modify it under the terms of the GNU Library General Public
  * License as published by the Free Software Foundation; either
  * version 2 of the License, or (at your option) any later version.
  *
  * This library is distributed in the hope that it will be useful,
  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  * Library General Public License for more details.
  *
  * You should have received a copy of the GNU Library General Public License
  * along with this library; see the file COPYING.LIB.  If not, write to
  * the Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor,
  * Boston, MA 02110-1301, USA.
  */
 
+// https://html.spec.whatwg.org/#htmliframeelement
+
 interface HTMLIFrameElement : HTMLElement {
+    [Reflect, URL] attribute DOMString src;
+    [Reflect] attribute DOMString srcdoc;
+    [Reflect] attribute DOMString name;
+    // FIXME: sandbox should be a DOMSettableTokenList.
+    [Reflect, TreatNullAs=NullString] attribute DOMString sandbox;
+    // Note: The seamless attribute was once supported, but was removed.
+    [Reflect] attribute boolean allowFullscreen;
+    [Reflect] attribute DOMString width;
+    [Reflect] attribute DOMString height;
+    [CheckSecurity=Node] readonly attribute Document? contentDocument;
+    readonly attribute Window? contentWindow;
+    [CheckSecurity=Node, RaisesException] Document? getSVGDocument();
+
+    // obsolete members
+    // https://html.spec.whatwg.org/#HTMLIFrameElement-partial
     [Reflect] attribute DOMString align;
-    [Reflect] attribute boolean allowFullscreen;
+    [Reflect] attribute DOMString scrolling;
     [Reflect] attribute DOMString frameBorder;
-    [Reflect] attribute DOMString height;
     [Reflect, URL] attribute DOMString longDesc;
+
     [Reflect, TreatNullAs=EmptyString] attribute DOMString marginHeight;
     [Reflect, TreatNullAs=EmptyString] attribute DOMString marginWidth;
-    [Reflect] attribute DOMString name;
-    [Reflect, TreatNullAs=NullString] attribute DOMString sandbox;
-    [Reflect] attribute DOMString scrolling;
-    [Reflect, URL] attribute DOMString src;
-    [Reflect] attribute DOMString srcdoc;
-    [Reflect] attribute DOMString width;
 
-    // Introduced in DOM Level 2:
-    [CheckSecurity=Node] readonly attribute Document contentDocument;
-
-    // Extensions
-    readonly attribute Window contentWindow;
-
-    [CheckSecurity=Node, RaisesException] Document getSVGDocument();
-
+    // Subresource Integrity
+    // https://w3c.github.io/webappsec/specs/subresourceintegrity/
+    // FIXME: The spec does not extend HTMLIFrameElement.
     [Reflect, RuntimeEnabled=SubresourceIntegrity] attribute DOMString integrity;
 };