Bugzilla

(In reply to Olli Pettay [:smaug][bugs@pettay.fi] from comment #4)
> What does "navigation starts" mean in this case? When an <a> element is clicked or when network connection is opened or what?
> 
> NavigationTiming code is notified here:  https://searchfox.org/mozilla-central/rev/d31e56f7b3c2c18b8071a7b2a2fb6b4e01e3d3e8/docshell/base/nsDocShell.cpp#9446, right before beforeunload, is that the only thing needed, some new notification?

Does this match https://html.spec.whatwg.org/#beginning-navigation step 14? 

> Invoke WebDriver BiDi navigation started with targetBrowsingContext, and a new WebDriver BiDi navigation status whose id is navigationId, status is "pending", and url is url.

That's where we need to be notified.

(In reply to Olli Pettay [:smaug][bugs@pettay.fi] from comment #4)
> What does "navigation starts" mean in this case? When an <a> element is clicked or when network connection is opened or what?
> 
> NavigationTiming code is notified here:  https://searchfox.org/mozilla-central/rev/d31e56f7b3c2c18b8071a7b2a2fb6b4e01e3d3e8/docshell/base/nsDocShell.cpp#9446, right before beforeunload, is that the only thing needed, some new notification?

Does this match https://html.spec.whatwg.org/#beginning-navigation step 14? 

> Invoke WebDriver BiDi navigation started with targetBrowsingContext, and a new WebDriver BiDi navigation status whose id is navigationId, status is "pending", and url is url.

That's where we need to be notified.

Edit: to answer the initial question, I think this needs to be emitted before the request is created, since it should occur before onbeforeunload runs?