Analyze: Layout:layout behaviour for different zoom level leading to scaling errors

[amartya4256]

Description
As we saw in the issue: eclipse-platform/eclipse.platform.swt#2166, GridLayout#layout had scaling errors because of the layout calculation done in points with int instead of float, leading to lose the decimal precision. This will be fixed by: eclipse-platform/eclipse.platform.swt#2381.
Hence, we should check out if this kind of behaviour is possible in other Layouts as well or if performing the layout with float values makes it better / doesn't cause any regression.
This issue focuses on the Layout implementation in SWT itself.

[amartya4256]

This can be scraped off not since we are going with a different approach eclipse-platform/eclipse.platform.swt#2502. We will fix it for all the control which implement computeSize. Should I close it?

[HeikoKlare]

Yes, but please create a replacement issue that tracks the computeSize fix for all Controls instead.

[akoch-yatta]

Closed due to #460