Eric,
Sorry you’re seeing this issue. It seems to be a problem with GTK3 and eclipse Mars (also Neon).
The workaround is to use GTK2. You can do this by placing the following lines in the myeclipse.ini file (in the same folder as the myeclipse executable):
--launcher.GTK_version
2
This would also help with excessive space around tab label text, if you see that. At this point, I’m not sure whether this will ultimately be fixed in eclipse or in GTK.
Please let us know if this helps.