Remove wxFileSystemWatcher::OnXXX() virtual methods documentation.

These functions don't exist any more (they had been present initially but were
removed in r61484 and r61476 for Unix and MSW respectively) so don't document
them.

See #12847.

git-svn-id: https://svn.wxwidgets.org/svn/wx/wxWidgets/trunk@66604 c3d73ce0-8a6f-49c7-b76d-6d57e0e08775

interface/wx/fswatcher.h

@@ -152,34 +152,6 @@ public:
         OnChange(), OnWarning() or OnError().
      */
     void SetOwner(wxEvtHandler* handler);
-
-protected:
-    /**
-        You may either connect your event handler to intercept file system
-        watcher events or override this member and handle them here.
-
-        Perform whatever action which is to be taken on file system change.
-     */
-    virtual void OnChange(int changeType, const wxFileName& path,
-                                        const wxFileName& newPath);
-
-    /**
-        You may either connect your event handler to intercept file system
-        watcher events or override this member and handle them here.
-
-        Perform whatever action which is to be taken when a warning condition
-        arises.
-     */
-    virtual void OnWarning(const wxString& errorMessage);
-
-    /**
-        You may either connect your event handler to intercept file system
-        watcher events or override this member and handle them here.
-
-        Perform whatever action which is to be taken when an error condition
-        arises.
-     */
-    virtual void OnError(const wxString& errorMessage);
 };