tdf#92982 vcl rendercontext: no need to tweak map mode in PaintBuffer()

This used to be necessary, but now that the "copy settings from the
window to the buffer" is always guarded with PaintBufferGuard, it's
actually one of the places that do modify the buffer settings without
undoing that later.

Change-Id: I7fde878635ffc7de7027d6d8f8de47935fc4870e

vcl/source/window/paint.cxx

@@ -129,7 +129,6 @@ private:
     vcl::Region* m_pChildRegion;
     Rectangle m_aSelectionRect;
     Rectangle m_aPaintRect;
-    MapMode m_aPaintRectMapMode;
     vcl::Region m_aPaintRegion;
     sal_uInt16 m_nPaintFlags;
     bool m_bPop : 1;
@@ -205,9 +204,6 @@ void PaintHelper::StartBufferedPaint()
 
     pFrameData->mbInBufferedPaint = true;
     m_bStartedBufferedPaint = true;
-
-    // Remember what was the map mode of m_aPaintRect.
-    m_aPaintRectMapMode = m_pWindow->GetMapMode();
 }
 
 void PaintHelper::PaintBuffer()
@@ -223,12 +219,6 @@ void PaintHelper::PaintBuffer()
     // window either above or in eg. an event handler]
     if (!getenv("VCL_DOUBLEBUFFERING_AVOID_PAINT"))
     {
-        // The map mode of m_pWindow and/or the buffer may have changed since
-        // StartBufferedPaint(), set it back to what it was, otherwise unwanted
-        // scaling or translating may happen.
-        m_pWindow->SetMapMode(m_aPaintRectMapMode);
-        pFrameData->mpBuffer->SetMapMode(m_aPaintRectMapMode);
-
         // Make sure that the +1 value GetSize() adds to the size is in pixels.
         Size aPaintRectSize;
         if (m_pWindow->GetMapMode().GetMapUnit() == MAP_PIXEL)