Artifacts when resizing column of TableViewer with StyledCellLabelProvider

[HeikoKlare]

Description
When resizing the columns of a TableViewer with StyledCellLabelProviders on a 175% monitor, rendering artifacts appear. It seems like the point/pixel values for some of the involed areas (clipping or the like) are not rounded correctly.

Reproduction
The issue can be reproduced with the following snippet and a 175% monitor monitor.
Main2.java

Expected Behavior
No rendering artifacts occur.

Additional knowledge
So this is probably related to the issue we see in #518.

[HeikoKlare]

For further information and actually also initial report of that issue see:

• https://bugs.eclipse.org/bugs/show_bug.cgi?id=291245
• https://bugs.eclipse.org/bugs/show_bug.cgi?id=414292