WIP(maintain/disabled): adding content document resolution

docs/api/maintain/disabled.md

@@ -1,6 +1,6 @@
 ---
 layout: doc-api.html
-tags: shadow-dom, service, argument-options
+tags: shadow-dom, service, argument-options, content-document
 ---
 
 # ally.maintain.disabled
@@ -49,6 +49,11 @@ A [`<service>`](../concepts.md#Service) interface, providing the `handle.disenga
 * **EXAMPLE:** [`ally.maintain.disabled` Example](./disabled.example.html)
 
 
+## Changes
+
+* Since `v#master` `options.context` resolves to the content document for `<iframe>` and `<object>` elements.
+
+
 ## Notes
 
 * **NOTE:** `ShadowHost`s are pierced and `ShadowRoot` content is made inert as well (except for closed shadow trees).

src/maintain/disabled.js

@@ -18,6 +18,7 @@
 import nodeArray from '../util/node-array';
 import queryFocusable from '../query/focusable';
 import elementDisabled from '../element/disabled';
+import getContentDocument from '../util/get-content-document';
 import {getParentComparator} from '../util/compare-position';
 
 function makeElementInert(element) {
@@ -38,6 +39,7 @@ const observerConfig = {
 class InertSubtree {
   constructor({context, filter} = {}) {
     this._context = nodeArray(context || document.documentElement)[0];
+    this._context = getContentDocument(this._context) || this._context;
     this._filter = nodeArray(filter);
 
     this.disengage = this.disengage.bind(this);