1482869 - 3-pane info pop-up not sticking to button on DevTools section zoom

Status: NEW

(DevTools :: Inspector, defect, P3)

Description

[Cristian Fogel [:cfogel]]

Attachment: devT_styleEditor_popUpInfoMovesOnScaling.gif

[Affected versions]:
- 62.0b16, 61.0.1, 63.0a1 (2018-08-13)

[Affected platforms]:
- win10x64, macOS 10.13, Ubuntu 16.04LTS

[Steps to reproduce]:
1. Launch firefox with a fresh profile;
2. Open devTools, inspector;
3. Move the mouse inside the devTools section;
4. Zoom in out *(CTRL+ / CTRL- / CTRL&MouseScroll)

[Expected result]:
- the pop-up remains near the 3pane inspector icon

[Actual result]:
- the pop-up moves around;
- it's also zoomed, probably intended;

[Regression range]:
- will double check asap, but pretty sure it's not a regression

[Additional notes]:
- attached screen recording with the issue;
- for nightly and release version, enter in the about:config page and enable all the preferences containing: "three-pane".