1505818 - Add the page information properly when back/forward navigation is used

Status: NEW

(Core :: Gecko Profiler, defect, P3)

Description

[Nazım Can Altınova [:canova][:canaltinova on phabricator]]

We landed the patches on bug 1417976. We are currently registering the pages on profiler. But we can do better with that. We can make the page registration lazy in some way.  Once we add a marker that refers to a page(`docshellId` + `historyId` pair)  we can create the `PageInformation`. We should do something like that because currently we are missing a point. 

Since we remove the `PageInformation` when we navigate to other page, if the profiler is not active, we might miss some `PageInformation` that some markers refer to.
 
For example, steps to reproduce:
- Open a web page
- Click on a link
- Start the profiler
- Go back to previous page
At this point, we don’t have the information of the current page in `RegisteredPages` array. It’s because we don’t register again when we navigate with the back/forward buttons.
To fix this we should either add a check for back/forward buttons to registration code or make the registration lazy.

Comment 1

[Julien Wajsberg [:julienw]]

Needinfo nazim to check that this is still a problem.

Comment 2

[Nazım Can Altınova [:canova][:canaltinova on phabricator]]

I can still see some missing innerWindowIDs in the profiles, so this is most likely still a problem. But probably it's less of a problem. I also filed Bug 1924681, which is I think more important than this, or can be investigated at the same time.

I'm changing the title of the bug to describe the issue and not the proposed solution. And thinking about it, I think the other proposed solution might be better instead of making the registration lazy: Add a check for back/forward buttons to registration code.