766371 - Add observer notification for first layout of new document when URL of docshell changes

Status: RESOLVED INCOMPLETE

(Core :: General, defect)

Description

[Frank Yan (:fryn)]

Please implement some kind of event or observer notification for the first layout of the new document when the URL of a docshell changes. For example, when navigating via a hyperlink from URL A to URL B, the location bar value changes from URL A to URL B, and onlocationchange is fired, and then a few moments later, URL A's document is removed from the content area, and URL B's document starts being laid out and painted, which is when this event or observer notification should be fired.

We need this for Search Tabs, so the sidebar can be displayed at the same time that we start laying out and painting the new page and not too early (e.g. onlocationchange) or too late (e.g. DOMContentLoaded).

Comment 1

[Boris Zbarsky [:bzbarsky]]

Does the "before-first-paint" notification we already send (for mobile stuff, right now) not do what you want?