tdf#63130 when getting the size, do not do a full paint

otherwise we end up doing double work when called from
ImplWindowFrameProc, which is the main driver of painting on the screen

This reduces the load time by 10%

Change-Id: I9eb82a180344875f707fbf3d8128351a35def6a8
Reviewed-on: https://gerrit.libreoffice.org/c/core/+/151879
Tested-by: Jenkins
Reviewed-by: Noel Grandin <noel.grandin@collabora.co.uk>
diff --git a/vcl/source/window/window.cxx b/vcl/source/window/window.cxx
index e52ee1b..1aa2291 100644
--- a/vcl/source/window/window.cxx
+++ b/vcl/source/window/window.cxx
@@ -2416,7 +2416,11 @@ Size Window::GetSizePixel() const
    {
        VclPtr<vcl::Window> xWindow( const_cast<Window*>(this) );
        mpWindowImpl->mpFrameData->maResizeIdle.Stop();
        mpWindowImpl->mpFrameData->maResizeIdle.Invoke( nullptr );
        // This is a copy of the code inside the resize Idle callback
        // __except__ that we are not calling the paint idle callback
        // which we don't want to do here, to avoid double work.
        if( mpWindowImpl->mbReallyVisible )
            xWindow->ImplCallResize();
        if( xWindow->isDisposed() )
            return Size(0,0);
    }