Sync HTML element interfaces H-K with the spec

Source/core/html/HTMLIFrameElement.idl

Index: Source/core/html/HTMLIFrameElement.idl
diff --git a/Source/core/html/HTMLIFrameElement.idl b/Source/core/html/HTMLIFrameElement.idl
index 568cd6b2b2429a572a605409ea91ccbd137ab2fa..5508d461ca52a473768b558f10c93cc9dfb4c4f7 100644
--- a/Source/core/html/HTMLIFrameElement.idl
+++ b/Source/core/html/HTMLIFrameElement.idl
@@ -18,28 +18,34 @@
  * Boston, MA 02110-1301, USA.
  */
 
+// https://html.spec.whatwg.org/#htmliframeelement
+
 interface HTMLIFrameElement : HTMLElement {
-    [Reflect] attribute DOMString align;
-    [Reflect] attribute boolean allowFullscreen;
-    [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 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();
 
-    // Introduced in DOM Level 2:
-    [CheckSecurity=Node] readonly attribute Document contentDocument;
-
-    // Extensions
-    readonly attribute Window contentWindow;
+    // obsolete members
+    // https://html.spec.whatwg.org/#HTMLIFrameElement-partial
+    [Reflect] attribute DOMString align;
+    [Reflect] attribute DOMString scrolling;
+    [Reflect] attribute DOMString frameBorder;
+    [Reflect, URL] attribute DOMString longDesc;
 
-    [CheckSecurity=Node, RaisesException] Document getSVGDocument();
+    [Reflect, TreatNullAs=EmptyString] attribute DOMString marginHeight;
+    [Reflect, TreatNullAs=EmptyString] attribute DOMString marginWidth;
 
+    // Subresource Integrity
+    // https://w3c.github.io/webappsec/specs/subresourceintegrity/
+    // FIXME: The spec does not extend HTMLIFrameElement.
     [Reflect, RuntimeEnabled=SubresourceIntegrity] attribute DOMString integrity;
 };