patch 8.2.4713: plugins cannot track text scrolling

Problem:    Plugins cannot track text scrolling.
Solution:   Add the WinScrolled event. (closes #10102)
diff --git a/src/proto/window.pro b/src/proto/window.pro
index 1954dfd..589dd09 100644
--- a/src/proto/window.pro
+++ b/src/proto/window.pro
@@ -13,14 +13,15 @@
 void win_move_after(win_T *win1, win_T *win2);
 void win_equal(win_T *next_curwin, int current, int dir);
 void entering_window(win_T *win);
+void curwin_init(void);
 void close_windows(buf_T *buf, int keep_curwin);
 int one_window(void);
 int win_close(win_T *win, int free_buf);
+void may_trigger_winscrolled(win_T *wp);
 void win_close_othertab(win_T *win, int free_buf, tabpage_T *tp);
 void win_free_all(void);
 win_T *winframe_remove(win_T *win, int *dirp, tabpage_T *tp);
 void close_others(int message, int forceit);
-void curwin_init(void);
 int win_alloc_first(void);
 win_T *win_alloc_popup_win(void);
 void win_init_popup_win(win_T *wp, buf_T *buf);