Tiny icons on high DPI screens

[idleberg]

Prerequisites

• Put an X between the brackets on this line if you have done all of the following:
  • Reproduced the problem in Safe Mode: https://flight-manual.atom.io/hacking-atom/sections/debugging/#using-safe-mode
  • Followed all applicable steps in the debugging guide: https://flight-manual.atom.io/hacking-atom/sections/debugging/
  • Checked the FAQs on the message board for common solutions: https://discuss.atom.io/c/faq
  • Checked that your issue isn't already filed: https://github.com/issues?utf8=✓&q=is%3Aissue+user%3Aatom
  • Checked that there is not already an Atom package that provides the described functionality: https://atom.io/packages

Description

When using a high DPI screen (sometimes known as "Retina" display), the icon will become unusably tiny. Screenshot from tool-bar-main:

Steps to Reproduce

1. Buy a high DPI screen :clown:
2. Install any package consuming the tool-bar service
3. View result

Expected behavior:

Screenshot from tool-bar-main with the fix from the PR applied.

Actual behavior:

Screenshot from tool-bar-main, without the fix

Reproduces how often:

100%

Versions

Atom : 1.60.0
Electron: 9.4.4
Chrome : 83.0.4103.122
Node : 12.14.1