While trying to figure out testing for bug 1700362, I discovered that reorder events aren't fired on the XUL browser OuterDocAccessible when a remote document is loaded. I don't think any real client cares, but we normally fire reorder events when a child is added and this is certainly inconsistent for parent process and content process documents.

To fix this, I guess we'd need to fire a reorder event in BrowserParent::RecvPDocAccessibleConstructor near where we call a11y::DocManager::RemoteDocAdded.

Note that this is probably one reason that accessible/tests/browser/events/browser_test_docload.js is currently broken and disabled.