Client::manager() takes an xcb_window_t as argument

client.h

@@ -319,7 +319,7 @@ public:
 #endif
     NET::WindowType windowType(bool direct = false, int supported_types = 0) const;
 
-    bool manage(Window w, bool isMapped);
+    bool manage(xcb_window_t w, bool isMapped);
     void releaseWindow(bool on_shutdown = false);
     void destroyClient();
 

manage.cpp

@@ -47,7 +47,7 @@ namespace KWin
  * reparenting, initial geometry, initial state, placement, etc.
  * Returns false if KWin is not going to manage this window.
  */
-bool Client::manage(Window w, bool isMapped)
+bool Client::manage(xcb_window_t w, bool isMapped)
 {
     StackingUpdatesBlocker stacking_blocker(workspace());