1520316 - Unnecessary construction & destruction of <popupnotification>s and children

Status: NEW

(Toolkit :: PopupNotifications and Notification Bars, enhancement, P3)

Description

[Tim Guan-tin Chien [:timdream] (please needinfo)]

Bug 823443 is implemented in a way that it will pick up the <popupnotification>s constructed in the mark-up from popup-notifications.inc, remove it from the DOM tree from browser.xul, and re-append it when necessary.

This causes the XBL bindings to construct-destruct immediately when the popup up is first shown. With the bindings migrated away from bindings to custom elements, we will be doing useless construction during startup.

The dirtiest way to fix this would be trying to construct the elements from markup lazily later, with MozXULElement.parseXULToFragment(). I don't know if we want/need to do that or not. I've got a talos push in bug 1518932 just to make sure this will not be a dependency of that bug 🤞🤞🤞.