widgets: Merge QWidgetRepaintManager::begin/endPaint into callsite

Change-Id: Iff5f78dcc8124bcecf53d42d920e74467937412a
Reviewed-by: Paul Olav Tvete <paul.tvete@qt.io>

src/widgets/kernel/qwidgetrepaintmanager.cpp

@@ -89,25 +89,6 @@ bool QWidgetRepaintManager::bltRect(const QRect &rect, int dx, int dy, QWidget *
     return store->scroll(tlwRect, dx, dy);
 }
 
-/*!
-    Prepares the window surface to paint a\ toClean region of the \a widget.
-
-    The \a toClean region might be clipped by the window surface.
-*/
-void QWidgetRepaintManager::beginPaint(QRegion &toClean, QBackingStore *backingStore)
-{
-    // Always flush repainted areas.
-    dirtyOnScreen += toClean;
-
-    backingStore->beginPaint(toClean);
-}
-
-void QWidgetRepaintManager::endPaint(QBackingStore *backingStore)
-{
-    backingStore->endPaint();
-    flush();
-}
-
 /*!
     Returns the region (in top-level coordinates) that needs repaint and/or flush.
 
@@ -1048,7 +1029,10 @@ void QWidgetRepaintManager::paintAndFlush()
     }
 #endif
 
-    beginPaint(toClean, store);
+    // Always flush repainted areas
+    dirtyOnScreen += toClean;
+
+    store->beginPaint(toClean);
 
     // Must do this before sending any paint events because
     // the size may change in the paint event.
@@ -1084,7 +1068,9 @@ void QWidgetRepaintManager::paintAndFlush()
         tlw->d_func()->drawWidget(store->paintDevice(), dirtyCopy, QPoint(), flags, 0, this);
     }
 
-    endPaint(store);
+    store->endPaint();
+
+    flush();
 }
 
 /*!

src/widgets/kernel/qwidgetrepaintmanager_p.h

@@ -180,9 +180,6 @@ private:
     void flush(QWidget *widget = nullptr);
     void flush(QWidget *widget, const QRegion &region, QPlatformTextureList *widgetTextures);
 
-    void beginPaint(QRegion &toClean, QBackingStore *backingStore);
-    void endPaint(QBackingStore *backingStore);
-
     QRegion dirtyRegion(QWidget *widget = nullptr) const;
 
     void updateLists(QWidget *widget);