Makes display roots be destroyed by client

services/ui/ws/test_utils.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/test_utils.h"
 
 #include <utility>
 
 #include "base/memory/ptr_util.h"
 #include "cc/output/copy_output_request.h"
@@ skipping 181 matching lines @@
   const uint32_t embed_flags = 0;
   WindowTree* tree = window_server_->EmbedAtWindow(
       root, shell::mojom::kRootUserID, ui::mojom::WindowTreeClientPtr(),
       embed_flags, base::WrapUnique(new WindowManagerAccessPolicy));
   tree->ConfigureWindowManager();
   return tree;
 }
 
 // TestWindowManager ----------------------------------------------------------
 
+void TestWindowManager::WmDisplayRemoved(int64_t display_id) {
+  got_display_removed_ = true;
+  display_removed_id_ = display_id;
+}
+
 void TestWindowManager::WmCreateTopLevelWindow(
     uint32_t change_id,
     ClientSpecificId requesting_client_id,
     mojo::Map<mojo::String, mojo::Array<uint8_t>> properties) {
   got_create_top_level_window_ = true;
   change_id_ = change_id;
 }
 
 void TestWindowManager::WmClientJankinessChanged(ClientSpecificId client_id,
                                                  bool janky) {}
@@ skipping 367 matching lines @@
     return nullptr;
   if (!tree->AddWindow(parent_client_id, client_window_id))
     return nullptr;
   *client_id = client_window_id;
   return tree->GetWindowByClientId(client_window_id);
 }
 
 }  // namespace test
 }  // namespace ws
 }  // namespace ui