X11: Wait for UnmapNotify before trying to remap

ui/events/platform/x11/x11_event_source.h

Index: ui/events/platform/x11/x11_event_source.h
diff --git a/ui/events/platform/x11/x11_event_source.h b/ui/events/platform/x11/x11_event_source.h
index 1537f6707ed7420a3f547e844540e8f4abe3b3c8..c878e172440046f6c2dfdee41ab502441c509cbe 100644
--- a/ui/events/platform/x11/x11_event_source.h
+++ b/ui/events/platform/x11/x11_event_source.h
@@ -62,6 +62,8 @@ class EVENTS_EXPORT X11EventSource {
   // functions which require a mapped window.
   void BlockUntilWindowMapped(XID window);
 
+  void BlockUntilWindowUnmapped(XID window);
+
   XDisplay* display() { return display_; }
   Time last_seen_server_time() const { return last_seen_server_time_; }
 
@@ -81,6 +83,10 @@ class EVENTS_EXPORT X11EventSource {
   // Handles updates after event has been dispatched.
   void PostDispatchEvent(XEvent* xevent);
 
+  // Block until receiving a structure notify event of |type| on |window|.
+  // Dispatch all encountered events prior to the one we're blocking on.
+  void BlockOnWindowStructureEvent(XID window, int type);
+
  private:
   static X11EventSource* instance_;