mus: Make sure window parenting happens in the window server.

services/ui/ws/display_manager.cc

 // Copyright 2016 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 "services/ui/ws/display_manager.h"
 
 #include <vector>
 
 #include "base/memory/ptr_util.h"
 #include "base/trace_event/trace_event.h"
@@ skipping 45 matching lines @@
 
 void DisplayManager::DestroyDisplay(Display* display) {
   if (pending_displays_.count(display)) {
     pending_displays_.erase(display);
   } else {
     for (const auto& pair : user_display_managers_)
       pair.second->OnWillDestroyDisplay(display);
 
     DCHECK(displays_.count(display));
     displays_.erase(display);
+    window_server_->OnDisplayDestroyed(display);
   }
   delete display;
 
   // If we have no more roots left, let the app know so it can terminate.
   // TODO(sky): move to delegate/observer.
   if (displays_.empty() && pending_displays_.empty())
     window_server_->OnNoMoreDisplays();
 }
 
 void DisplayManager::DestroyAllDisplays() {
@@ skipping 142 matching lines @@
 void DisplayManager::OnPrimaryDisplayChanged(int64_t primary_display_id) {
   // TODO(kylechar): Send IPCs to WM clients first.
 
   // Send IPCs to any DisplayManagerObservers.
   for (const auto& pair : user_display_managers_)
     pair.second->OnPrimaryDisplayChanged(primary_display_id);
 }
 
 }  // namespace ws
 }  // namespace ui