Bug 187907 – [Meta] Ensure element queues are properly pushed/popped from custom element reactions stack

• Status: RESOLVED
• Resolution: DUPLICATE
• Component: DOM

[Frédéric Wang (:fredw)]

These are the places where such operations are mentioned in the spec:

1) create an element for a token
   https://html.spec.whatwg.org/#create-an-element-for-the-token
   This is at least making one test fail in custom-elements/parser/parser-sets-attributes-and-children.html and causing the ASSERT in bug 187802.

2) insert a foreign element
   https://html.spec.whatwg.org/#insert-a-foreign-element
   This is at least making another test fail custom-elements/parser/parser-sets-attributes-and-children.html.

3) Operations, attributes, setters, or deleters annotated with the [CEReactions] extended attribute
   https://html.spec.whatwg.org/#custom-element-reactions:custom-element-reactions-stack-5
   Hopefully, we already do all the necessary calls, but bug 187851 will make sure we don't miss anything.

[Ryosuke Niwa]

We need to be very careful with respect to how this work affects perf.

[Ryosuke Niwa]

We don't really need a meta bug like this separate from the bug 154907.

*** This bug has been marked as a duplicate of bug 154907 ***