QWidgetBackingStore: clean up around dirtyOnScreenWidgets

The QVector dirtyOnScreenWidgets was aggregated by pointer, which
makes no sense, as a QVector is just as large as a pointer (and even
in Qt 6, when it will be larger, it's not going to be horrible). But
this complicated the code quite a bit.

Aggregate by value instead (it's just one of three such vectors now).

Drive-by fixes:

- use QVector::removeAll() instead of rolling your own

- port two indexed loops to ranged ones. In the first case, it's safe,
  as the loop body clearly doesn't touch the iteratee (it's just a
  std::accumulate). In the second, the question no longer applies, as
  we're now using a consume loop.

Change-Id: Icd4ac13bb4a6f9a783f0adf2fb6a5bdfacd1f91a
Reviewed-by: Friedemann Kleint <Friedemann.Kleint@qt.io>
Reviewed-by: Volker Hilsheimer <volker.hilsheimer@qt.io>

0 files changed, 0 insertions, 0 deletions