In conformance with the requirements of the spec PR at
https://github.com/whatwg/html/pull/9546, this change adds support for
the “switch” attribute for type=checkbox “input” elements — which is
shipping in Safari (since Safari 17.4). This change also implements
support for exposing it to AT users with role=switch.
Currently, the following JS snippet will hang indefinitely:
new DOMParser().parseFromString("<object>", "text/html");
Because the document into which the object is inserted is not active. So
the task queued to run the representation steps will never run.
This patch implements the spec steps to rerun the representation steps
when the active state changes, and avoid the hang when the object is
created in an inactive document.
