Manual High DPI test: Create Dnd pixmap with device pixel ratio.

Apply the device pixel ratio from the widget unless Shift is pressed.

Task-number: QTBUG-46068
Task-number: QTBUG-50938
Change-Id: Ib806b7e545fa228043566800d22d1002728732bf
Reviewed-by: Shawn Rutledge <shawn.rutledge@theqtcompany.com>

tests/manual/highdpi/dragwidget.cpp

@@ -168,7 +168,11 @@ void DragWidget::mousePressEvent(QMouseEvent *event)
     mimeData->setData("application/x-hotspot",
                       QByteArray::number(hotSpot.x()) + " " + QByteArray::number(hotSpot.y()));
 
-    QPixmap pixmap(child->size());
+    const qreal dpr = devicePixelRatioF() > 1 && !(QGuiApplication::keyboardModifiers() & Qt::ShiftModifier)
+        ? devicePixelRatioF() : 1;
+
+    QPixmap pixmap(child->size() * dpr);
+    pixmap.setDevicePixelRatio(dpr);
     child->render(&pixmap);
 
     QDrag *drag = new QDrag(this);