X11: Wait for UnmapNotify before trying to remap

ui/events/platform/x11/x11_event_source.cc

 // 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.
 
 #include "ui/events/platform/x11/x11_event_source.h"
 
 #include <X11/Xatom.h>
 #include <X11/XKBlib.h>
 #include <X11/Xlib.h>
 
@@ skipping 123 matching lines @@
   // not yet.
   continue_stream_ = true;
   while (XPending(display_) && continue_stream_) {
     XEvent xevent;
     XNextEvent(display_, &xevent);
     ExtractCookieDataDispatchEvent(&xevent);
   }
 }
 
 void X11EventSource::BlockUntilWindowMapped(XID window) {
-  XEvent event;
-  do {
-    // Block until there's a message of |event_mask| type on |w|. Then remove
-    // it from the queue and stuff it in |event|.
-    XWindowEvent(display_, window, StructureNotifyMask, &event);
-    ExtractCookieDataDispatchEvent(&event);
-  } while (event.type != MapNotify);
+  BlockOnWindowStructureEvent(window, MapNotify);
+}
+
+void X11EventSource::BlockUntilWindowUnmapped(XID window) {
+  BlockOnWindowStructureEvent(window, UnmapNotify);
 }
 
 Time X11EventSource::UpdateLastSeenServerTime() {
   base::TimeTicks start = base::TimeTicks::Now();
 
   DCHECK(display_);
 
   if (!dummy_initialized_) {
     // Create a new Window and Atom that will be used for the property change.
     dummy_window_ = XCreateSimpleWindow(display_, DefaultRootWindow(display_),
@@ skipping 57 matching lines @@
   }
 
   if (xevent->type == EnterNotify &&
       xevent->xcrossing.detail != NotifyInferior &&
       xevent->xcrossing.mode != NotifyUngrab) {
     // Clear stored scroll data
     ui::DeviceDataManagerX11::GetInstance()->InvalidateScrollClasses();
   }
 }
 
+void X11EventSource::BlockOnWindowStructureEvent(XID window, int type) {
+  XEvent event;
+  do {
+    // Block until there's a StructureNotify event of |type| on |window|. Then
+    // remove it from the queue and stuff it in |event|.
+    XWindowEvent(display_, window, StructureNotifyMask, &event);
+    ExtractCookieDataDispatchEvent(&event);
+  } while (event.type != type);
+}
+
 void X11EventSource::StopCurrentEventStream() {
   continue_stream_ = false;
 }
 
 void X11EventSource::OnDispatcherListChanged() {
   if (!hotplug_event_handler_) {
     hotplug_event_handler_.reset(new X11HotplugEventHandler());
     // Force the initial device query to have an update list of active devices.
     hotplug_event_handler_->OnHotplugEvent();
   }
 }
 
 }  // namespace ui