Drop refresh method on D-Bus interface

The method is nowhere inside KWin called, nor used as a slot.
It's also not used from any of the KCMs and the method does not
do what the name says. It just shows and hides a window as big
as the screen geometry.

REVIEW: 104418

org.kde.KWin.xml

@@ -17,7 +17,6 @@
     <method name="toggleCompositing">
       <annotation name="org.freedesktop.DBus.Method.NoReply" value="true"/>
     </method>
-    <method name="refresh"/>
     <method name="doNotManage">
       <arg name="name" type="s" direction="in"/>
     </method>

workspace.cpp

@@ -1160,18 +1160,6 @@ bool Workspace::isNotManaged(const QString& title)
     return false;
 }
 
-/**
- * Refreshes all the client windows
- */
-void Workspace::refresh()
-{
-    QWidget w(NULL, Qt::X11BypassWindowManagerHint);
-    w.setGeometry(Kephal::ScreenUtils::desktopGeometry());
-    w.show();
-    w.hide();
-    QApplication::flush();
-}
-
 /**
  * During virt. desktop switching, desktop areas covered by windows that are
  * going to be hidden are first obscured by new windows with no background

workspace.h

@@ -538,7 +538,6 @@ public:
 
 public slots:
     void addRepaintFull();
-    void refresh();
 
     // Keybindings
     void slotSwitchDesktopNext();