Minimize/Maximize Icons Scaled Incorrectly

[HeikoKlare]

The minimize/maximize icons of part stacks are scaled incorrectly under specific conditions. This is how it looks like:

Note: I was only able to produce this issue in dark mode so far.

How to reproduce

You can reproduce the behavior as follows:

1. Set up at least two monitors with different zoom values (e.g., 100% and 125%)
2. Start an Eclipse application with rescaling on runtime activated (and auto scale mode quarter).
3. Place the workbench window on the 100% monitor. Note: if you move it between both monitors now, the minimize/maximize icons will be rescaled correctly.
4. Move the workbench window from the 100% to the 125% monitor.
5. Change focus to another application on the 100% monitor.
6. Move the workbench window from the 125% to the 100% monitor.

Now the icons are scaled incorrectly for the active part stack. As soon as you switch focus to some other application again, the icons will be rescaled correctly.

[akoch-yatta]

Had a look at it and know where the issue comes from. I'll try to find a good fix