tdf#134054 Qt5 really scale the toolbox button

I missed that code in the HiDPI patch. Instead of some fixed 25px
size, use the real content size and ask the QStyle for the real
size.

Change-Id: I227190baab2c1716aa40ef6d16d55dbded0830cc
Reviewed-on: https://gerrit.libreoffice.org/c/core/+/97538
Tested-by: Jenkins
Reviewed-by: Jan-Marek Glogowski <glogow@fbihome.de>
diff --git a/vcl/qt5/Qt5Graphics_Controls.cxx b/vcl/qt5/Qt5Graphics_Controls.cxx
index ee7b43d..6f54e6f 100644
--- a/vcl/qt5/Qt5Graphics_Controls.cxx
+++ b/vcl/qt5/Qt5Graphics_Controls.cxx
@@ -935,8 +935,12 @@ bool Qt5Graphics_Controls::getNativeControlRegion(ControlType type, ControlPart 
            }
            else if (part == ControlPart::Button)
            {
                contentRect = QRect(boundingRect.left(), boundingRect.top(),
                                    upscale(25, Round::Ceil), upscale(25, Round::Ceil));
                QStyleOptionToolButton option;
                option.arrowType = Qt::NoArrow;
                option.features = QStyleOptionToolButton::None;
                option.rect = downscale(QRect({ 0, 0 }, contentRect.size()));
                contentRect = upscale(
                    subControlRect(QStyle::CC_ToolButton, &option, QStyle::SC_ToolButton));
                boundingRect = contentRect;
                retVal = true;
            }