ImplDeleteOverlapBackground is empty now

Change-Id: Ie022bb51da1f57b9db9362bb34423d9c921f4264

include/vcl/window.hxx

@@ -585,8 +585,6 @@ public:
 
     SAL_DLLPRIVATE void                 ImplUpdateAll( bool bOverlapWindows = true );
 
-    SAL_DLLPRIVATE void                 ImplDeleteOverlapBackground();
-
     SAL_DLLPRIVATE void                 ImplControlFocus( GetFocusFlags nFlags = GetFocusFlags::NONE );
 
     SAL_DLLPRIVATE void                 ImplMirrorFramePos( Point &pt ) const;

vcl/source/window/clipping.cxx

@@ -812,10 +812,6 @@ bool Window::ImplRestoreOverlapBackground( vcl::Region& rInvRegion )
     return false;
 }
 
-void Window::ImplDeleteOverlapBackground()
-{
-}
-
 void Window::ImplInvalidateAllOverlapBackgrounds()
 {
     vcl::Window* pWindow = mpWindowImpl->mpFrameData->mpFirstBackWin;
@@ -837,8 +833,6 @@ void Window::ImplInvalidateAllOverlapBackgrounds()
                 if ( !pWindow->mpWindowImpl->mpOverlapData->mpSaveBackRgn )
                     pWindow->mpWindowImpl->mpOverlapData->mpSaveBackRgn = new vcl::Region( aRect2 );
                 pWindow->mpWindowImpl->mpOverlapData->mpSaveBackRgn->Exclude( aRect1 );
-                if ( pWindow->mpWindowImpl->mpOverlapData->mpSaveBackRgn->IsEmpty() )
-                    pWindow->ImplDeleteOverlapBackground();
             }
 
         }

vcl/source/window/winproc.cxx

@@ -1574,18 +1574,6 @@ static bool ImplHandleLongPress(vcl::Window *pWindow, const SalLongPressEvent& r
 
 static void ImplHandlePaint( vcl::Window* pWindow, const Rectangle& rBoundRect, bool bImmediateUpdate )
 {
-    // give up background save when system paints arrive
-    vcl::Window* pSaveBackWin = pWindow->ImplGetWindowImpl()->mpFrameData->mpFirstBackWin;
-    while ( pSaveBackWin )
-    {
-        vcl::Window* pNext = pSaveBackWin->ImplGetWindowImpl()->mpOverlapData->mpNextBackWin;
-        Rectangle aRect( Point( pSaveBackWin->GetOutOffXPixel(), pSaveBackWin->GetOutOffYPixel() ),
-                         Size( pSaveBackWin->GetOutputWidthPixel(), pSaveBackWin->GetOutputHeightPixel() ) );
-        if ( aRect.IsOver( rBoundRect ) )
-            pSaveBackWin->ImplDeleteOverlapBackground();
-        pSaveBackWin = pNext;
-    }
-
     // system paint events must be checked for re-mirroring
     pWindow->ImplGetWindowImpl()->mnPaintFlags |= IMPL_PAINT_CHECKRTL;