Preview::test_ComboEnsureVisible unstable

[Michał Sawicz]

The test ensuring that expanded combo in the preview is fully visible is unstable still.

I was able to reproduce locally with:

$ while parallel -i -j10 make -C builddir testPreview -- 1 2 3 4 5 6 7 8 9 0; do :; done

See attached a screenshot of the window when it fails, you can see that indeed the view didn't scroll as far down as it should have.

This seems like a Qt problem since we're simply calling ListView::positionViewAtIndex(index, ListView.Contain) on it.

Or, maybe it's the fact that the combo is still growing when the list tries to position it?

ProblemType: Bug
DistroRelease: Ubuntu 16.04
Package: unity8 8.11+16.04.20160301-0ubuntu1
ProcVersionSignature: Ubuntu 4.4.0-9.24-generic 4.4.3
Uname: Linux 4.4.0-9-generic x86_64
ApportVersion: 2.20-0ubuntu3
Architecture: amd64
CurrentDesktop: Unity
Date: Sat Mar 5 11:32:38 2016
SourcePackage: unity8
UpgradeStatus: No upgrade log present (probably fresh install)