m_nExtStyle isn't used in gtk[2|3]

Change-Id: Id03d0ee0d4aa29df85c7fcbcb59e1f769b63862f
diff --git a/vcl/inc/unx/gtk/gtkframe.hxx b/vcl/inc/unx/gtk/gtkframe.hxx
index 51977c25..ad61504 100644
--- a/vcl/inc/unx/gtk/gtkframe.hxx
+++ b/vcl/inc/unx/gtk/gtkframe.hxx
@@ -179,7 +179,6 @@ class GtkSalFrame : public SalFrame
    GdkWindow*                      m_pForeignTopLevel;
    GdkNativeWindow                 m_aForeignTopLevelWindow;
    SalFrameStyleFlags              m_nStyle;
    SalExtStyle                     m_nExtStyle;
    GtkSalFrame*                    m_pParent;
    std::list< GtkSalFrame* >       m_aChildren;
    GdkWindowState                  m_nState;
diff --git a/vcl/unx/gtk/gtksalframe.cxx b/vcl/unx/gtk/gtksalframe.cxx
index 1f41463..24544f4 100644
--- a/vcl/unx/gtk/gtksalframe.cxx
+++ b/vcl/unx/gtk/gtksalframe.cxx
@@ -973,7 +973,6 @@ void GtkSalFrame::InitCommon()
    m_nVisibility       = GDK_VISIBILITY_FULLY_OBSCURED;
    m_bSendModChangeOnRelease = false;
    m_pIMHandler        = nullptr;
    m_nExtStyle         = 0;
    m_pRegion           = nullptr;
    m_ePointerStyle     = static_cast<PointerStyle>(0xffff);
    m_bSetFocusOnMap    = false;
@@ -1357,13 +1356,8 @@ void GtkSalFrame::askForXEmbedFocus( sal_Int32 i_nTimeCode )
    GetGenericData()->ErrorTrapPop();
}

void GtkSalFrame::SetExtendedFrameStyle( SalExtStyle nStyle )
void GtkSalFrame::SetExtendedFrameStyle(SalExtStyle)
{
    if( nStyle != m_nExtStyle && ! isChild() )
    {
        m_nExtStyle = nStyle;
        updateWMClass();
    }
}

SalGraphics* GtkSalFrame::AcquireGraphics()
diff --git a/vcl/unx/gtk3/gtk3gtkframe.cxx b/vcl/unx/gtk3/gtk3gtkframe.cxx
index 26ffb0a..009ac68 100644
--- a/vcl/unx/gtk3/gtk3gtkframe.cxx
+++ b/vcl/unx/gtk3/gtk3gtkframe.cxx
@@ -1077,7 +1077,6 @@ void GtkSalFrame::InitCommon()
    m_nVisibility       = GDK_VISIBILITY_FULLY_OBSCURED;
    m_bSendModChangeOnRelease = false;
    m_pIMHandler        = nullptr;
    m_nExtStyle         = 0;
    m_pRegion           = nullptr;
    m_pDropTarget       = nullptr;
    m_pDragSource       = nullptr;
@@ -1314,13 +1313,8 @@ void GtkSalFrame::Init( SystemParentData* pSysData )
    //FIXME: Handling embedded windows, is going to be fun ...
}

void GtkSalFrame::SetExtendedFrameStyle( SalExtStyle nStyle )
void GtkSalFrame::SetExtendedFrameStyle(SalExtStyle)
{
    if( nStyle != m_nExtStyle && ! isChild() )
    {
        m_nExtStyle = nStyle;
        updateWMClass();
    }
}

SalGraphics* GtkSalFrame::AcquireGraphics()