Stabilize tst_QSpinBox::sizeHint()

The test function used to flake on Linux occasionally.
8e6ede7cd131682161180bfab0cc46686674709b provided a fix. While it
seemed to work, further analysis has shown that the root cause is
event sequence in case of multiple paint events.

This patch re-engineers the test function:

1. Allocate test widget on the stack instead of the heap.
2. Send layout requests posted by QHBoxLayout constructor and
QLayout::addWidget() before showing the widget.
3. Remove calls to QCoreApplication::processEvents().
They are unnessecary, because
- the size hint request counter is supposed to increase (by any number)
- QTRY_VERIFY processes events anyway until the counter increases or it
times out.

Pick-to: 6.5 6.4 6.2
Change-Id: I54998483725cbdd4899ba6f5469d7dae0980ab1d
Reviewed-by: Friedemann Kleint <Friedemann.Kleint@qt.io>

0 files changed, 0 insertions, 0 deletions