user32: Add test for ComboBox repositioning behavior (try 2).

[Marvin]

Hi,

While running your changed tests on Windows, I think I found new failures.
Being a bot and all I'm not very good at pattern recognition, so I might be
wrong, but could you please double-check?
Full results can be found at
http://testbot.winehq.org/JobDetails.pl?Key=19658

Your paranoid android.


=== W7PRO (32 bit msg) ===
msg.c:8219: Test failed: did not get zero count as expected (1).