Nvidia resume from suspend corruption
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This test ensures the screen is not corrupted after resume from suspend on nvidia cards.

Setup:

Actions:
#. Ensure unity is running on a machine with a nvidia GPU using the proprietary nvidia driver
#. Put the machine to sleep
#. Resume the machine from sleep
#. Observe the area where the launcher would normally show

Expected Result:
  The screen should not display any visual corruption once X is finished updating after a resume.
