1342975 - Box model moves when selector highlighter is on and scrolling down the page

Status: RESOLVED DUPLICATE of bug 1351081

(DevTools :: Inspector, defect, P2)

Description

[Bogdan Maris, Desktop Test Engineering]

Attachment: Screencast showing the issue

[Affected versions]:
- latest Nightly 54.0a1

[Unaffected versions]:
- latest Developer Edition 53.0a2
- Fx 52 beta 9
- Fx 51.0.1

[Affected platforms]:
- Mac OS X 10.11
- Windows 10 x64
- Ubuntu 16.04 x32

[Steps to reproduce]:
1. Visit demopage https://bug1312103.bmoattachments.org/attachment.cgi?id=8837541
2. Open Inspector
3. Select <aside id="playground">...<.aside>
4. From the Rules tab activate the Selector Highlighter for #playground
5. Scroll inside the demopage

[Expected result]:
- Box model does not move when scrolling the page.

[Actual result]:
- Box model moves while user scrolls the page.

[Regression range]:
- This is a recent regression, it's a regression from 2016-05-09:

m-c:

Last good revision: 0a7831d838f793a263456df62f95a615472a7f95 (2017-02-15)
First bad revision: a9ec72f82299250e6023988e238931bbca0ef7fa (2017-02-16)
Pushlog:
https://hg.mozilla.org/mozilla-central/pushloghtml?fromchange=0a7831d838f793a263456df62f95a615472a7f95&tochange=a9ec72f82299250e6023988e238931bbca0ef7fa

m-i:

Last good revision: 2ae8554e0989e12e9ef5755a4171841b02df7f11
First bad revision: 07de05d8060cb97df8df4aaf371b7f23da4b46cb
Pushlog:
https://hg.mozilla.org/integration/autoland/pushloghtml?fromchange=2ae8554e0989e
12e9ef5755a4171841b02df7f11&tochange=07de05d8060cb97df8df4aaf371b7f23da4b46cb

Looks like the following bug has the changes which introduced the regression:
https://bugzilla.mozilla.org/show_bug.cgi?id=1312103

07de05d8060c	Matteo Ferretti — Bug 1312103 - Avoid scrolling latency on highlighters given by APZ; r=pbro

[Additional notes]:
- Attached is a screencast showing the issue.
- Build from the left is latest Nightly and build from the right is Fx 51.0.1

Comment 1

[Patrick Brosset <:pbro>]

Inspector bug triage (filter on CLIMBING SHOES).

Comment 2

[Paul Silaghi, QA [:pauly]]

since bug 1312103 landed in Fx 53

Comment 3

[Randell Jesup [:jesup] (needinfo me)]

matteo: can we get this fixed for 53?  Do we need to back out bug 1312103 from 53, or is this something we can live with

Comment 4

[Liz Henry (:lizzard)]

Too late for 53. We could still take a patch for 54 though.

Comment 5

[Gerry Chang [:gchang]]

Too late for 54.

Comment 6

[Matteo Ferretti [:zer0] [:matteo]]

Unfortunately we cannot do much. This is due APZ, and elements positioned fixed (or sticky when they behaves like fixed).
I mitigate a bit the effects in bug 1351081, but we cannot remove totally the effect, because the scrolling is happening in a different process.