1950716 - New-Tab Page sometimes briefly shows a loading tooltip near bottom-left: "Read firefox-settings-attachments.cdn.mozilla.net"

Status: NEW

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

Description

[Daniel Holbert [:dholbert]]

STR:

1. Open Firefox, and pay close attention to the bottom-left of your Firefox window as it opens to the new-tab page.

ACTUAL RESULTS:
As the new-tab page loads, there's sometimes a brief flicker of a tooltip-like notification at the bottom left corner that says:

Read firefox-settings-attachments.cdn.mozilla.net

EXPECTED RESULTS:
No such notification, maybe? The flicker is too fast to see the content, and hence is kind of distracting and annoying. These sorts of tooltips are shown as a progress indicator when we're loading data from a website, but new-tab is meant to be mostly local (with remote data pulled in, but that sourcing of remote data is meant to be behind-the-scenes mostly and shouldn't result in loading indicators like this, especially very-brief flickery ones)

Here's a profile that I captured which shows this tooltip-notification in the screenshots track at around t=1.770s:
https://share.firefox.dev/3EVHpT0

(This is with a fresh profile that I just created today, where I had simply opened and closed Firefox a bunch of times with MOZ_PROFILER_STARTUP=1 environmental variable specified in my terminal, watching for this issue until I was able to see & capture it.)

Comment 1

[Daniel Holbert [:dholbert]]

Here's a narrowed profile showing the moment where this notification is available (plus a little bit of time before/after it):
https://share.firefox.dev/41tVjV7

If you hover the screenshot track in the middle of this^ profile link, you can see the tooltip at the bottom left of the screenshot.

Comment 2

[Daniel Holbert [:dholbert]]

Attachment: screenshot taken from the profile showing the tooltip

Comment 3

[Daniel Holbert [:dholbert]]

Attachment: screenshot showing another version of the tooltip for `ads-img.mozilla.org`

(In reply to Daniel Holbert [:dholbert] from comment #0)

ACTUAL RESULTS:
As the new-tab page loads, there's sometimes a brief flicker of a tooltip-like notification at the bottom left corner that says:

Read firefox-settings-attachments.cdn.mozilla.net

Here's another one where the message is for a different domain: Read ads-img.mozilla.org

(Again, it's too brief to actually read; just a momentary flicker.)
https://share.firefox.dev/4kjzFu4

Comment 4

[Daniel Holbert [:dholbert]]

(I don't know offhand how to suppress these "loading some network resource" tooltip notifications -- they're part of the Firefox UI that's layered over web content -- but presumably there's some way to do so, for privileged content at least.)