UserAgent: Mozilla/5.0 (X11; Linux x86_64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/54.0.2840.59 Safari/537.36

Steps to reproduce the problem:
Test URL: http://podium-tonyz3-dev-appsframework-server.podium-dev.is.borg.google.com:25757/ide/project/269d2f?token=4arqo390it3hjpo1

1. Move the mouse to the city, as shown in https://screenshot.googleplex.com/MDqxXUobR4u.png
2. ":after" pseudo element should appear (in the exmaple, "Mountain View"

What is the expected behavior?
The CSS used for the ":after" pseudo element is:
position: absolute;
Expect the element should appear just above the original element, like https://screenshot.googleplex.com/vLgkJsW4d3w.png

What went wrong?
The pseudo element appears right side of the original element. If turning CSS with 'top' field, the element will jump to far away wrong position.

Did this work before? N/A 

Does this work in other browsers? N/A

Chrome version: 54.0.2840.59  Channel: stable
OS Version: 3.13.0-95-generic
Flash Version: Shockwave Flash 23.0 r0