qWaitForWindowActive was called in two test functions without
activating the relevant widget.
This patch adds widget activation before calling
qWaitForWindowActive.
Helper function verifyColor:
A loop made six comparison attempts of widget size, pixel color and
image with a 200ms waiting time after each unsuccessful attempt.
The widget size was tested at the beginning of the loop.
The test was failed on the first size mismatch, which occurred when
verifyColor was called before the widget was rendered.
That has lead to flakiness (e.g. on openSuSE).
This patch encapsules each check in a lambda and calls qWaitFor to
ensure event processing until each condition has become true.
Change-Id: Ic98f93c8acf41459bc728f2969fe8b01768048dd
Reviewed-by: Tor Arne Vestbø <tor.arne.vestbo@qt.io>