vcl: stop vcl::Window clobbering mnRefCnt itself.

Change-Id: If1926c8ecc94c3b9786a3f255371b440c482a155
diff --git a/vcl/qa/cppunit/lifecycle.cxx b/vcl/qa/cppunit/lifecycle.cxx
index cbe0ef6..5f5f4e3 100644
--- a/vcl/qa/cppunit/lifecycle.cxx
+++ b/vcl/qa/cppunit/lifecycle.cxx
@@ -68,8 +68,7 @@ void LifecycleTest::testVirtualDevice()

void LifecycleTest::testMultiDispose()
{
    VclPtrInstance<WorkWindow> xWin((vcl::Window *)NULL,
                                    WB_APP|WB_STDWORK);
    VclPtrInstance<WorkWindow> xWin(nullptr, WB_APP|WB_STDWORK);
    CPPUNIT_ASSERT(xWin.get() != NULL);
    xWin->disposeOnce();
    xWin->disposeOnce();
diff --git a/vcl/source/window/window.cxx b/vcl/source/window/window.cxx
index 89679ba..bcf21e9 100644
--- a/vcl/source/window/window.cxx
+++ b/vcl/source/window/window.cxx
@@ -1211,7 +1211,6 @@ void Window::ImplInitAppFontData( vcl::Window* pWindow )

void Window::ImplInitWindowData( WindowType nType )
{
    mnRefCnt = 0;
    mpWindowImpl = new WindowImpl( nType );

    meOutDevType        = OUTDEV_WINDOW;