Avoid blocking while mapping an X11 window

ui/events/platform/x11/x11_event_source.h

 // Copyright 2014 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #ifndef UI_EVENTS_PLATFORM_X11_X11_EVENT_SOURCE_H_
 #define UI_EVENTS_PLATFORM_X11_X11_EVENT_SOURCE_H_
 
 #include <stdint.h>
 
 #include <memory>
@@ skipping 55 matching lines @@
   // xserver that |w| has been mapped; StructureNotifyMask events on |w| are
   // pulled out from the queue and dispatched out of order.
   //
   // For those that know X11, this is really a wrapper around XWindowEvent
   // which still makes sure the preempted event is dispatched instead of
   // dropped on the floor. This method exists because mapping a window is
   // asynchronous (and we receive an XEvent when mapped), while there are also
   // functions which require a mapped window.
   void BlockUntilWindowMapped(XID window);
 
-  void BlockUntilWindowUnmapped(XID window);
-
   XDisplay* display() { return display_; }
 
   // Returns the timestamp of the event currently being dispatched.  Falls back
   // on GetCurrentServerTime() if there's no event being dispatched, or if the
   // current event does not have a timestamp.
   Time GetTimestamp();
 
   // Returns the root pointer location only if there is an event being
   // dispatched that contains that information.
   base::Optional<gfx::Point> GetRootCursorLocationFromCurrentEvent() const;
@@ skipping 40 matching lines @@
   bool continue_stream_ = true;
 
   std::unique_ptr<X11HotplugEventHandler> hotplug_event_handler_;
 
   DISALLOW_COPY_AND_ASSIGN(X11EventSource);
 };
 
 }  // namespace ui
 
 #endif  // UI_EVENTS_PLATFORM_X11_X11_EVENT_SOURCE_H_