1543998 - Add UserTiming markers for Discovery Stream events

Status: NEW

(Firefox :: New Tab Page, enhancement, P3)

Description

[Andrei Oprea [:andreio]]

Attachment: Screenshot 2019-04-12 at 15.40.33.png

UserTiming markers are useful in profile captures to signal when specific events happened.
detect-user-session-start.js notifies when the new tab page became visible to the user.
We should add something similar for when sections have rendered, data finished downloading or other events that might be interesting.

Comment 1

[Andrei Oprea [:andreio]]

Attachment: Screenshot 2019-04-30 at 20.05.55.png

It looks like we get this for free if we turn on react-dev. Maybe the scope of this bug should change to see if we can use the profile data to plot timing information.

Comment 2

[Andrei Oprea [:andreio]]

Attachment: Screenshot 2019-05-09 at 15.47.30.png

Do you think it makes sense to include/use profiler markers in the performance numbers?
What I like about this is that it's easy to get this information, you only have to start the browser and it's already computed for you. This could easily be included as part of the review process when changing a component: we could compare before and after applying a patch and look at duration field of several browser startups for that component (like Topsites in my screenshot).
The cool thing is that using the profiler you can make network requests so it's working with real world data.

Comment 3

[Jessilyn Davis]

Let us know what you think for 69

Comment 4

[Gavin Suntop [:gvn] (they/he)]

I think adding these markers probably makes sense!