Makes display roots be destroyed by client

services/ui/ws/window_server.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 "services/ui/ws/window_server.h"
 
 #include <set>
 #include <string>
 
 #include "base/logging.h"
@@ skipping 188 matching lines @@
 }
 
 ServerWindow* WindowServer::GetWindow(const WindowId& id) {
   // kInvalidClientId is used for Display and WindowManager nodes.
   if (id.client_id == kInvalidClientId) {
     for (Display* display : display_manager_->displays()) {
       ServerWindow* window = display->GetRootWithId(id);
       if (window)
         return window;
     }
+    // WindowManagerDisplayRoots are destroyed by the client and not held by
+    // the Display.
+    for (auto& pair : tree_map_) {
+      if (pair.second->window_manager_state()) {
+        ServerWindow* window =
+            pair.second->window_manager_state()->GetOrphanedRootWithId(id);
+        if (window)
+          return window;
+      }
+    }
   }
   WindowTree* tree = GetTreeWithId(id.client_id);
   return tree ? tree->GetWindow(id) : nullptr;
 }
 
 void WindowServer::SchedulePaint(ServerWindow* window,
                                  const gfx::Rect& bounds) {
   Display* display = display_manager_->GetDisplayContaining(window);
   if (display)
     display->SchedulePaint(window, bounds);
@@ skipping 601 matching lines @@
 void WindowServer::OnUserIdAdded(const UserId& id) {
   activity_monitor_map_[id] = base::MakeUnique<UserActivityMonitor>(nullptr);
 }
 
 void WindowServer::OnUserIdRemoved(const UserId& id) {
   activity_monitor_map_.erase(id);
 }
 
 }  // namespace ws
 }  // namespace ui